QUITO - Lava was rising anew in the crater of Ecuador's Reventador volcano on Monday, a day after bursts of ash forced temporary closure of the capital's airport.

Geophysics Institute technician Patricio Ramon said explosion rocked the 11,686-foot (3,562-meter) volcano and lava poured its flanks on Sunday. Officials suspended flights into Quito's airport for three hours as a precaution.

Heightened activity at Reventador could threaten a highway and two oil pipelines, Ramon said. Both lines were operating normally on Monday.

The volcano experienced a violent eruption in 2002 that shot ash 10 miles (17 kilometers) high, blasted a flow of volcanic material nearly 5 miles (8 kilometers) down its slopes and dusted Quito, 60 miles (100 kilometers) to the west with a thick layer of ash.

Fumaroles were rising as well from two volcanos in neighboring Colombia, the 17,598-foot (5,363-meter) Nevado de Huila and the 8,694-foot (2,650-meter) Machin.

Colombia's Institute of Geology and Mining issued alerts and 450 people voluntarily evacuated their homes near Machin, according to officials there.