COLOMBO, Dec. 7 -- Sri Lankan authorities issued fresh landslide warnings todaywith rains lashing areas already devastated by a powerful cyclone, as the death toll rose to 618.

A chain of tropical storms and monsoonal rains has battered Southeast and South Asia, triggering landslides, flooding vast tracts, and cutting off communities from Sumatra Island's rainforests to the highland plantations of Sri Lanka.

At least 1,812 people have been killed in the natural disasters rolling across Sri Lanka, Indonesia, Malaysia, Thailand and Vietnam over the past two weeks.

Indonesia's president on Sunday vowed to step up aid, with demonstrators rallying after the country's death toll surpassed 900.

More than two million people in Sri Lanka-nearl...