An erupting Chilean volcano which sent a towering plume of ash across South America has forced thousands to leave their homes, grounded airline flights in southern Argentina and coated ski resorts with a gritty layer of dust instead of snow. The 2,240-meter-high Puyehue volcano began erupting two days ago, sending a 10 kilometre-high cloud of ash all the way to the Atlantic Ocean and even into the southern Buenos Aires province, hundreds of miles to the northeast.Authorities in Chile have said that they tried to persuade the residents near the volcano to leave with immediate effect as their is an increasing danger of toxic gas and flash floods. Deputy Interior Minister Rodrigo Ubilla has however said that about 50 families in the Rininahue area have refused to abandon their homes. About 4,000 people had been evacuated from more than 22 communities by Monday.Airport officials have said that airports have been closed in the region around San Carlos de Bariloche and in Trelew on the Atlantic coast.