"There is still a very serious threat of an attack. The threat level is at severe, indicating the high likelihood of an attempted terrorist attack at some stage, and I urge the public to remain vigilant," he added.

In the aftermath of the arrests, Britain's air services continued to move more slowly than normal. At London's busy Heathrow airport on Sunday, about one-third of the flights were cancelled.

Officials blamed stringent new screening rules imposed on Aug. 10, which include a ban on all carry-on luggage.

Police arrested 24 people across England on Thursday in connection with an alleged plot to blow up as many as 10 passenger planes flying between Britain and the United States. Authorities have accused the suspects of planning to smuggle explosives onto the flights.

One suspect was released without charge, and a court will decide Monday on the detention of another.

The suspects are said to be British nationals with links to Pakistan. The Bank of England released the names of 19 suspects on Friday and said that their assets had been frozen.

Brothers accused of leading plot

On Saturday, officials in Pakistan said two brothers arrested in that country and in Britain have emerged as lead figures in the investigation of the alleged plot.

Rashid Rauf, who was arrested along the border between Pakistan and Afghanistan about a week ago, has been listed as a "key person" in the investigation, authorities with Pakistan's Foreign Ministry said.

Rauf's brother, Tayib Rauf, 22, was arrested in Britain. Police there have refused to comment on reports that a third brother is among the 40 people who have been detained in the two countries.

What are the lessons from this war? I think there have been three main ones. First, the international community must be prepared to condemn all war crimes against civilians without hesitation and strenuous efforts must be made to bring perpetrators to justice, not least as a means of preventing new generations of embittered victims. Second, the UN Security Council has been turned into a sort of club for the benefit of US interests, threatening to bankrupt its legitimacy. Last week, Kofi Annan confessed his "profound disappointment" at Security Council delays over Lebanon, admitting "its inability to act sooner has badly shaken the world's faith in its authority and integrity". Thirdly, Tony Blair has further degraded what little stock he has on the international stage as a diplomat or "honest broker".

ON WAR crimes, the evidence is now considerable. According to Human Rights Watch (HRW), Israel's Lebanon offensive "systematically failed to distinguish between combatants and civilians". In some cases, "attacks constitute war crimes", it said. It is equally obvious that, with their deadly barrage of Katyushas or longer-range "Khaibar-1" missiles, Hezbollah rained indiscriminate death on to cities in northern Israel.

What was especially shocking, however, was the massively one-sided nature of the killings and the fact that Israel sought to justify its actions by pointing to Hezbollah tactics. Detailed investigations by HRW disproved the Israeli line that Hezbollah had positioned its missiles in residential locations. The Israeli claim was false.

Lest we forget, Israel's offensive in the sovereign state of Lebanon was a clear act of aggression under international law. Indeed it is the fifth separate occasion Israel has invaded Lebanon.

Israel's indiscriminate and disproportionate use of force was in breach of humanitarian law. The calculated destruction of Lebanon's infrastructure - roads, bridges, factories, hospitals, generators and oil containers - all constituted collective punishment, another imputable crime under international law. War crimes like this must not be ignored.

The second key point is that the UN Security Council, with its 15 countries (and inner club of five big powers calling the shots), can never be relied on to respond to crises like this without prevarication and politicking that will cost lives. We desperately need UN reform and, in future, the UN's full General Assembly must be empowered to act. The General Assembly must be far more prepared to convene emergency sessions, ones that can speedily call for diplomacy, talks, ceasefires and investigations and settlements.

Third, it simply has to be acknowledged that the UK under Tony Blair has played an unconscionable role in this and other critical situations in the Middle East. The simple truth is that in countless situations no progress can be made if the world is reliant on either the US or UK as supposed "honest brokers". Israel's military hardware, for example, is overwhelmingly American-made (with some hi-tech British components) and throughout this war, the UK government allowed massive 1,000lb "bunker-buster" bombs passage through UK airports.

Heaven knows what holidaymakers at Prestwick made of the news that bunker-busters bound for the Israeli air force had been sitting alongside them at the airport. Or indeed, what they thought of recent reports that Sunday's Israeli air offensive against the Rweis district of southern Beirut involved these weapons. People at the scene reported at least seven bodies, including three children, being pulled out of the rubble of demolished apartment blocks after the attack.

Even cluster bombs have been among the arsenal of US weapons supplied to Israel. In light of all this, are we really to suppose Messrs Bush and Blair could ever have had a sensible role in negotiating a peace settlement? After they'd given Israel a green light to continue its onslaught in Lebanon? Aiding and abetting war crimes is an unusual basis on which to broker peace.

THE stark truth is Tony Blair's policies have failed miserably over Lebanon, just as they have over Iraq. This time his efforts were too little, too late, and his "diplomacy" riddled with bias. Let us put it this way: how many civilians, including women and children, have to die before Blair's diplomacy becomes anything other than a dead letter? Even now, achieving a lasting peace out of this inferno will be incredibly difficult. But it requires - as a minimum - even-handedness and a genuine respect for justice.

On the one hand, I have condemned Hezbollah's rocket attacks. I genuinely understand the suffering of many people in Israel. During a visit a few years ago, I was particularly moved by an encounter I had with an Israeli mother whose son, a soldier in the Israeli Defence Forces, was killed by a Palestinian sniper at a West Bank checkpoint. Still raw with grief, she nevertheless managed to speak of peace, compromise and reconciliation, not the hatred and bitterness you might have expected.

On the other hand, Lebanese people have suffered grievously. My experience is that people in this multi-ethnic democracy are genuinely committed to finding a peaceful solution to live with Israel.

The calculated viciousness of the slaughter in this war and the compromised, immoral response of nations like the US and the UK are heinous acts from which recovery will be difficult. But one route away from future anarchy and further conflict is a renewal of a meaningful sense of justice for the people of this region.

If your home has been bombed, on either side of the border, there should be an independent fact-finding body to whom you can report this. Amnesty International has called for an International Humanitarian Fact-Finding Commission to be established.

This could investigate incidents where serious violations of the Geneva Conventions are alleged to have taken place. This is where the UN can exert influence, breaking out of the deadlock of Security Council politicking and getting down to facts on the ground.

We can't allow the war crimes of this conflict to be buried along with innocent civilians. For example, the shocking killings at Qana - when dozens of Lebanese civilians died on 30 July while sheltering from an Israel air raid - have been met only with a hasty internal Israeli investigation that quickly exonerated its forces of any wrongdoing. It has been dismissed by Amnesty International as a whitewash, typical of the Israeli army's flawed self-investigations.

Qana has happened before. In 1996 an Israeli air force bombing at Qana killed 106 Lebanese civilians seeking refuge in a UN shelter. The UN's own report, initially highly critical of Israel, was later toned down following, it seems, pressure from Israel.

This time around, the UN must demand these sham inquiries are set aside and real investigations allowed. Bombing outrages followed by condemnations, lightweight "investigations" and inaction are not the way forward for the bereaved and injured in Lebanon, just as they are not for their partners in suffering in Israel.

THERE is already an excess of historical grievance - because justice and a "lasting peace" is so often promised by politicians on all sides, then snatched away again. The UN General Assembly should tackle this head-on. If the ceasefire holds, the GA should act to implement all outstanding UN resolutions regarding Palestine, Israel and Lebanon - and instigate reform of the addled Security Council. Withdrawal of Israeli forces from Lebanon should be the kick-start for the withdrawal of Israel from all occupied territories.

Meanwhile, Tony Blair's actions over Lebanon and Iraq have demonstrated one thing: he has lost all moral authority and is no longer fit to be Prime Minister of this country.

- Bianca Jagger is a human rights campaigner