The Institute of Vulcanology warned that the eruption could intensify with ash rising as high as 1000 to 2000 metres, posing a threat to air traffic at Guatemala's international airport.

"Ash could spread over Guatemala City due to the direction of the wind," the country's disaster response office said in a statement.

The last major eruption of Pacaya, in May 2010, claimed the life of a television journalist, drove thousands of people from their homes and forced the closure of the Guatemala City airport for five days.

The 2552 metre-high Pacaya is 50 kilometres south of the capital and one of three active volcanoes in Guatemala.

Mount Etna is spitting lava more violently than it has in years, and scientists are baffled as to why. Despite being the world's most-studied volcano, the Sicilian mountain is also its most unpredictable. The volcano is raging. Fountains of lava, some taller than the Eiffel Tower, shoot from its mouth every few weeks, flowing in red-hot streams into the surrounding valleys. There have been 13 eruptions since the beginning of February. Mount Etna, 3,329 meters (10,922 feet) high, towers majestically above the Sicilian city of Catania. In June, the United Nations Educational, Scientific and Cultural Organization (UNESCO) will decide whether to list it as a World Heritage Site. Etna is considered the most heavily studied volcano in the world, and it is thoroughly wired with sensors. In addition to lava, Etna spits out vast amounts of data - several gigabytes a day, coming from magnetic field sensors, GPS altimeters and seismic sensors.
Despite this wealth of data, Etna still poses a conundrum to scientists. "The eruptions in recent weeks have been unusually fierce and explosive," reports German volcanologist Boris Behncke, who monitors the mountain together with a few hundred colleagues at Italy's National Institute of Geophysics and Volcanology (INGV). "There have been lava fountain events in the past, but rarely in such rapid succession." Behncke has fallen under Etna's spell. During the day, he maps the lava flows; at night, he hikes along its slopes. His Twitter hash tag is "@etnaboris." The volcano is the first thing he sees when he looks out of his bedroom window every morning. "This time, the range of ash fall is much wider than usual," says Behncke. A layer of black ash covers cars as far as 50 kilometers (31 miles) away.

The authorities in Chile have ordered the evacuation of more than 2,000 people living near the Copahue volcano in the south of the country.

They issued a red alert - the highest possible - saying the volcano could erupt imminently.

The evacuation will affect some 460 families living within a 25km (15 miles) radius of Copahue.

The 2,965m (nearly 10,000ft) volcano sits in the Andes cordillera, on the border with Argentina.

"This red alert has been issued after monitoring the activity of the volcano and seeing that it has increased seismic activity," Interior Minister Andrew Chadwick said in a news conference.

"There is a risk that it can start erupting."

The BBC's Gideon Long, in the Chilean capital, Santiago, says that thousands of minor earth tremors have been registered in the area in recent days.

Mount Etna is spitting lava more violently than it has in years, and scientists are baffled as to why. Despite being the world's most-studied volcano, the Sicilian mountain is also its most unpredictable.

The remote volcano in the northern Kuriles is probably in eruption, the latest SVERT report and satellite images suggest. A plume of gas and steam, and possibly some minor amounts ash was seen with the MODIS sensor onboard the NASA Terra satellite this morning. Satellite data also indicate that activity had likely already started in early May, because a small thermal anomaly can be traced back on archive pictures to 7 May. One should take into account that frequent dense cloud cover often prevents such observations, so activity could have started earlier than that. It is not known what kind of activity is occurring at the volcano. Possibilities include some minor explosive (strombolian ?) activity at the summit, or lava flows that might be reaching the sea and produce the steam plume observed. The last eruption of the volcano was (probably) in 2004. - Volcano Discovery

SERNAGEOMIN has raised the alert level to orange. Since May 15, a progressive increase in seismic activity as well emissions of gas and now some ash have been observed. Both earthquakes related to rock fracturing and fluid movements have picked up in numbers and possibly indicate a new magmatic intrusion on its way. This scenario is confirmed by the start of small ash emissions and glow at the crater which is visible at night. The plume of gas and ash could be seen from space by the MODIS sensor, stretching about 100 km to the southeast. Copahue volcano had already experienced a first increase of activity in December, and a second one in January. No eruption followed and alert was lowered to green in April before returning to yellow again soon after. - Volcano Discovery

Astronauts aboard the International Space Station (ISS) photographed this striking view of Pavlof Volcano on May 18, 2013. The oblique perspective from the ISS reveals the three dimensional structure of the ash plume, which is often obscured by the top-down view of most remote sensing satellites.

Situated in the Aleutian Arc about 625 miles (1,000 kilometers) southwest of Anchorage, Pavlof began erupting on May 13, 2013. The volcano jetted lava into the air and spewed an ash cloud 20,000 feet (6,000 meters) high. When photograph ISS036-E-2105 (top) was taken, the space station was about 475 miles south-southeast of the volcano (49.1° North latitude, 157.4° West longitude). The volcanic plume extended southeastward over the North Pacific Ocean.

An increase in seismicity since 26 April triggered VSI to rise the alert status from 2 to 3 on a scale of 1-4 (from "Waspada," "watch" to Siaga," alert). For the moment, only degassing has been observed as surface activity. A similar increase in seismic activity was observed in Oct 2012, when the alert was raised as well and then reduced again in November. The last eruption at the volcano occurred in 2009. - Volcano Discovery

At 5 a.m. Tuesday morning, the Turrialba Volcano, located east of the province of Cartago, began to spew gas and ash from two crater openings, the Volcanological and Seismological Observatory of Costa Rica (Ovsicori) reported. By 8:30 a.m. a significant amount of volcanic material was released from the two openings of volcano, "which may indicate that these materials come from deep areas," Ovsicori said. "It is uncertain what will happen.
Volcanologists are heading to the site to evaluate the activity," the statement said. Experts said Tuesday's activity is "normal for an active volcano such as Turrialba," but they recommended all nearby communities remain vigilant in coming hours. The released material fell into grasslands and communities in the canton of Turrialba and reached some three kilometers west of the crater. The trail of gases and ash can be seen from various locations in the provinces of Cartago, San José, Heredia and Limón. Public access to the volcano area was closed last year due to the activity. The Turrialba Volcano also emitted material in 2007, 2010 and 2012. The last eruptions of the volcano were in 1884. - Tico Times