Prosecutors have opened a murder investigation, said Svetlana Petrenko, spokeswoman for the Moscow prosecutor's office. Investigators suspect the killing could be linked to her work, Vyacheslav Rosinsky, Moscow's first deputy prosecutor, said on state-run Rossiya television.

Rosinsky said a pistol and bullets were found at the site of the crime. The RIA-Novosti news agency, citing police officials, reported that Politkovskaya was shot twice, the second time in the head.

The ITAR-Tass news agency reported that work was under way on a composite sketch of the attacker based on footage recorded by a security camera at the building. The assailant, believed to have acted alone, wore black.

Politkovskaya, who wrote for the Novaya Gazeta newspaper, chronicled the killings, tortures and beatings of civilians by Russian servicemen in Chechnya in reports that put her on a collision course with the authorities but won her numerous international awards.

"People sometimes pay with their lives for saying out loud what they think. People can even get killed just for giving me information," Reporters Without Borders quoted her as saying at a press freedom conference in Vienna in December.

She also wrote a book critical of Russian President
Vladimir Putin and his military campaign in Chechnya, documenting widespread abuse of civilians by government troops. And she was a persistent critic of Chechnya's Moscow-backed Prime Minister Ramzan Kadyrov, accusing his security forces of kidnapping and torturing civilians.

In "Putin's Russia," Politkovskaya wrote of more than a million soldiers and officers who have passed through the Chechnya experience.

"Poisoned by a war on their own territory, they have become a serious factor affecting civilian life. They can no longer simply be left out of the social equation," she wrote.

Politkovskaya began reporting on Chechnya in 1999 during Russia's second military campaign there, concentrating less on military engagements than on the human side of the war. She wrote about the Chechen inhabitants of refugee camps and wounded Russian soldiers - until she was banned from visiting the hospitals, said Oleg Panfilov, director of the Moscow-based Center for Journalism in Extreme Situations.

"Whenever the question arose whether there is honest journalism in Russia, almost every time the first name that came to mind was Politkovskaya," he said.

Politkovskaya had frequently received threats, Panfilov said. A few months ago, unknown assailants had tried unsuccessfully to break into a car her daughter, Vera, was driving, he said.

In 2001, she fled to Vienna, Austria, for several months after receiving e-mail threats alleging that a Russian police officer she had accused of committing atrocities against civilians was intent on revenge. The officer, Sergei Lapin, was detained in 2002 but the case against him was closed the following year.

"There are journalists who have this fate hanging over them. I always thought something would happen to Anya, first of all because of Chechnya," Panfilov said, referring to Politkovskaya by her nickname.

In 2004, she fell seriously ill with symptoms of food poisoning after drinking tea on a flight from Moscow to southern Russia during the school hostage crisis in Beslan. Her colleagues suspected the incident was an attempt on her life.

She was one of the few people to enter the Moscow theater where Chechen militants seized hundreds of hostages in October 2002 to try negotiating with the rebels. She later devoted much of her investigative reporting to that crisis, in which 129 victims died, the overwhelming majority succumbing to the gas used by special forces to knock out the hostage-takers.

"Anna was a hero to so many of us, and we'll miss her personally, but we'll also miss the information that she and only she was brave enough and dedicated enough to dig out and make public," said Joel Simon, executive director of the New York-based Committee to Protect Journalists.

The 46-nation Council of Europe, a leading human rights watchdog whose executive body is currently led by Russia, called for her death to be investigated quickly and convincingly.

"We have all lost a strong voice of the kind which is indispensable in any genuine democracy," said the council's secretary general, Terry Davis.

Politkovskaya's murder is the highest-profile killing of a journalist in Russia since the July 2004 slaying of Paul Klebnikov, editor of the Russian edition of Forbes magazine.

Russia has become one of the deadliest countries for journalists. Twenty-three journalists were killed in Russia between 1996 and 2005, many in Chechnya, according to the Committee to Protect Journalists. At least 12 have been murdered in contract-style killings since Putin came to power, Simon said.

"None of those have been adequately investigated," he said. "We do know that record creates an environment where those who might seek to carry out this murder would feel that there would be few likely consequences."

In addition to her daughter, Politkovskaya is survived by a son, Ilya, Panfilov said.

During her career, Politkovskaya received more than 10 awards and prizes, including an award for human rights reporting from the London-based Amnesty International; a freedom of speech award from the Paris-based watchdog Reporters Without Borders; and a journalism and democracy award from the Organization for Security and Cooperation in Europe.

The US State Department said it was "shocked and profoundly saddened" by what appeared to be at least the 13th contract killing of a journalist since Mr Putin took power in 2000. European governments expressed similar sentiments.

But from the Kremlin there was silence. Not even speculation on websites that Politkovskaya's death was a birthday present for Mr Putin, who was 54 on Saturday, the day she was killed, could provoke a government reaction.

Among the thousand or so protesters at vigils in Moscow and St Petersburg, there was no doubt that someone in the Kremlin knew something about the reporter's death.

The words scrawled across the giant photograph of Politkovskaya in Pushkin Square, Moscow, said it all: "The Kremlin has killed freedom of speech."

A portrait of Mr Putin bore the words: "You are responsible for everything."

Politkovskaya's newspaper, the bi-weekly Novaya Gazeta, which is partly owned by the former Soviet leader Mikhail Gorbachev, was due to run her latest Chechnyan expose.

Although she had not filed her article, the deputy chief editor, Vitaly Yaroshevsky, said it lifted the lid on torture and kidnapping of civilians by officers loyal to Chechnya's Moscow-backed prime minister Ramzan Kadyrov.

Mr Kadyrov, 30, a protégé of Mr Putin, was one of Politkovskaya's foremost enemies. She was to testify against him in a case over the kidnapping and killing of two civilians. Politkovskaya, 48, was shot twice at close range as she returned to her flat from shopping. The mother of two was found in the lift, with a 9mm Makarov pistol by her side.

CCTV showed a man, in black and with a baseball cap, hurrying from the building.

Politkovskaya made many powerful enemies in the FSB, the spy agency that succeeded the KGB, over scores of trips to Chechnya that exposed Russian brutality in the province and detailed the horrific conditions of ordinary Russian soldiers there.

She received many threats and survived an alleged attempt to poison her tea on a flight in 2004.

Her son regularly checked her car for bombs and she knew death was a possibility. "If it happens, it happens," she told The Daily Telegraph this summer. Last December, she told a conference on press freedom: "People sometimes pay with their lives for saying out loud what they think."

Few are confident a police investigation will uncover the truth. No other journalist's murder in the past six years has been solved.

But the killing of so famous a figure, two weeks after the murder of the reforming deputy head of the central bank, Andrei Kozlov, has convinced some that hard-liners in the Kremlin have begun to act with impunity as 2008 presidential elections draw closer.

"Those who killed her were absolutely convinced that it is now possible in Russia to do such things openly, without even bothering to camouflage it as an accident," said a former dissident, Sergey Grigoryants.

Chance to unite

Young and old took to the streets to throw their weight behind the campaign of Mr Rosales, a middle-class Social Democrat who governs the state of Zulia, on the Colombian border.

Many claimed that they were seeking liberty and democracy and that made Mr Rosales their only option:

"The problem of the opposition is that before we had a lot of candidates and people couldn't make up their minds whom to support," one woman said.

"Right now we have just one candidate and I believe that we have a better shot if we have just one candidate against Chavez."

For some it was simply a day out to enjoy the sunshine, but for most it was a chance to listen to a speech by Mr Rosales, who declared that Venezuela was "at a crossroads".

Mr Rosales condemned what he called the cheque book diplomacy of Mr Chavez, accusing him of giving away Venezuela's oil wealth to foreign powers.

If Mr Rosales can keep up this kind of pressure against his rival, the election results may not necessarily be a foregone conclusion.

But for now, Mr Chavez still enjoys a clear lead in opinion polls because of a sense of loyalty that poor and working-class voters feel towards him.

A large number of people, including political party activists, professionals and civic society representatives, have gathered around the official residence of Prime Minister Girija Prasad Koirala in Baluwatar--the venue of the talks--exerting pressure for reaching tangible decisions to end the political conflict for good. State-run Nepal Television said 32 leaders, four each from the seven Alliance parties and the Maoists are taking part in the parley and the venue is entirely closed for others except a few civic society representatives and talks facilitators.

Leaders coming out of the summit venue during lunch break expressed optimism about the possibility of some breakthrough in the ongoing talks but none has yet disclosed the exact content of the talks.

UML general secretary Madhav Nepal has claimed that Sunday's summit talks would come to a concrete conclusion. "Our party has been actively working on how the summit talks can be made a success," he said during a tea reception hosted by Nepali Congress on Saturday.

Finance minister and Nepali Congress leader Dr Ram Saran Mahat also said, "Sunday's summit talks will contribute to achieving sustainable democracy and permanent peace in the country." United Nations Assistant Secretary-General Kul Chandra Gautam, who also joined the NC's tea reception pn Saturday, said that the Nepalese were able to take decisions on major issues and that the UN would extend all possible help in the peace process here.

He described the latest political developments in Nepal as "very positive" and expressed the hope that the political leaders, who have been working hard for the success of the summit talks, would be able to find a solution to the problems facing the country.

It is likely that the summit meeting would prolong for few days.