Several airlines Thursday canceled flights in and out of Buenos Aires due to an ash cloud spewing from a volcano in neighboring Chile, officials told AFP.

"All flights by Aerolineas Argentinas and Austral have been canceled until midday," an airport official said as Argentina marks the Copa America competition which has been drawing thousands of football fans.

Seven international arrivals and nine departures from abroad were also shelved due to Chile's Puyehue volcano which has caused havoc for air travel and tourism since it erupted in early June for the first time in five decades.

"The airports are operational, but the companies can decide to cancel flights because of the ash," the official added.

An Air France flight which had been due to land at Ezeiza international airport in the Argentine capital Thursday was diverted to the Guarulhos airport in Sao Paulo, Brazil.

Airports in the resort town of Bariloche and the Patagonian hub Neuquen have remained closed since June 4 after winds spread the volcanic ash across much of southern Argentina, intermittently grounding commercial flights and airports in and around the country's capital.

Flights from airports across South America -- including hubs in Montevideo, the Chilean capital Santiago and southern Brazilian cities -- have also been hit as ash clouds swept around the Southern Hemisphere to linger over Australia and New Zealand.

Argentina is currently playing host to the Copa America -- the world's oldest international football tournament dating back to 1916 -- which has been dubbed a continental finishing school for the World Cup.

Matches are being played around the country and drawing tens of thousands of international and domestic soccer fans, whose travel plans have been complicated by the flight chaos.

A group of Mexican football fans was Thursday trying desperately to travel to Mendoza, some 1,000 kilometers (600 miles) from the Argentine capital to cheer Mexico on Friday as it battles for a quarter-final place against Peru.

Puyehue, which rumbled to life early last month for the first time since 1960, is high in the Andes mountains, 870 kilometers (540 miles) south of Santiago and near the border with Argentina.

On Monday Argentine President Cristina Kirchner announced a slew of economic measures to mitigate the effects of the ash.

Citing a "real tragedy" in Argentina caused by the volcano, Kirchner said the government would double social benefits, as well as defer tax payments and obligations for the hardest-hit Andean cities and towns, including the skiing resort city of Bariloche and Villa La Angostura in the Andes.

The Patagonia mountain range in southwestern Argentina, home to both cities, was declared an environmental disaster area after a massive layer of volcanic ash was dumped there following an eruption.

earlier related report
More pressure at Iceland volcano than at last blast: expert
Reykjavik (AFP) July 7, 2011 - Activity at an Icelandic volcano subsided some Thursday, but an expert warned it still looked ready to blow, as magma pressure underneath Mount Hekla was stronger than before its last eruption.

"Activities at Mount Hekla have calmed down a little bit," said University of Iceland geophysicist Pall Einarsson, who sounded the alarm on Wednesday that Hekla looked ready to erupt.

Gunnar Gudmundsson, a geophysicist at the Icelandic Meteorological Office, also told AFP "things have calmed down some (and) there have been no earthquakes".

While such observations are promising, volcanoes are notoriously temperamental and Einarsson cautioned an eruption still appeared imminent.

"Measurement of the magma pressure indicates that it has been more in the last few days than before the volcano's last eruption in 2000," he told AFP, adding: "it is a fact that Hekla is ready to erupt and that could happen at any time".

The Hekla volcano is close to the ash-spewing Eyjafjoell, which last year caused the world's biggest airspace shutdown since World War II, affecting more than 100,000 flights and eight million passengers.

The volcano, dubbed by Icelanders in the Middle Ages as the "Gateway to Hell", is one of Iceland's most active, having erupted about 20 times over the past millennium, and about once a decade for the past 50 years.

Hekla eruptions are known to be extremely varied and hard-to-predict, with some lasting only a matter of days and others lasting months and even years.

While scientists say a blast at Hekla would probably not produce as much ash as Eyjafjoell or the Grimsvoetn eruption in May and thereby not as many flight disruptions, there is concern for people in the surrounding area.

"If people are in the wrong place at the wrong time they can be in danger. The last time Hekla erupted in 2000 the state radio gave an half an hour warning and that is not neccesarily enough for people who are in area," warned Anders Hansen, the head of the Hekla Museum in nearby Leirubakki.

At 1,491 metres (4,892 feet) and located about 110 kilometres (70 miles) east of Reykjavik, Hekla is so active that scientists estimate about 10 percent of the tephra -- the solid matter ejected when a volcano erupts -- produced in Iceland over the past millennium, or about five cubic kilometres, comes from this one volcano.