Rescue workers on Monday recovered 29 more bodies buried under debris, Sri Lankan emergency services said, bringing the death toll caused by torrential rains to 164.
More than 104 people have been listed as missing across seven southern districts hit by monsoons and a tropical cyclone since Thursday.
The bad weather has affected 471,542 people and displaced 75,236 others, according to the Disaster Management Center, the central body coordinating relief operations.
The displaced are living in 336 temporary shelters, emergency officials said.
The worst affected area is the south-central district of Ratnapura, where 71 have been killed and more than 69,000 people affected.
Other affected districts include Kalutara with 53 deaths and Matara with 21 deaths. More than 200,000 people have been affected in both districts.
Sri Lanka has sought assistance from the international community, following the worst rains since 2003.
India has sent two vessels and 2,000 military personnel to assist in rescue operations. Divers and a helicopter were also provided by New Delhi.
The Indian High Commissioner in Sri Lanka, Taranjit Singh Sandhu, said Indian rescue teams had joined local teams to help Sri Lanka “in its hour of need”.
Meanwhile, the UN mobilized several of its agencies to support relief efforts.
The UNICEF has donated water containers, water purification tables and tarpaulin sheets for immediate distribution, while the World Health Organization is working with the Health Ministry to deploy medical teams.
More rains have been predicted in the coming days and fresh warnings have been issued to people living close to the island’s main rivers.
In 2016, Sri Lanka suffered severe flooding and landslides that claimed more than 100 lives.—Agencies