A local resident wears a facial mask amid a landscape covered by ash near Futaleufu, some 170 km from Chaiten, 07 May 2008

Authorities in southern Chile have forced the remaining residents who live near the Chaiten volcano to leave the region, after a strong eruption spewed hot rocks.

Officials say the residents had to leave because of what are known as pyroclastic flows, which are fast moving currents of hot gas and rocks.

The long-dormant volcano began erupting last Friday. About 4,000 people have been evacuated from a town bearing the same name as the volcano.

Winds have also blown volcanic ash into neighboring Argentina, grounding flights and forcing some schools to close.

Major airlines have canceled flights to the Patagonia region due to concerns that ash from the erupting Chaiten volcano could damage airplane engines.