The number of people known to have been killed in floods and landslides in Sri Lanka rose to 151, officials said on Sunday, as the country appealed for international assistance.

The state-run disaster management centre said 111 people were still missing and 95 people were injured in hospital after the worst torrential rains since 2003.

The United Nations is assisting in relief efforts in response to a government appeal. It promised to donate water purification tablets, tarpaulins, and water containers for the displaced.

The World Health Organisation will support medical teams in affected areas, and the United States and Pakistan also promised consignments of relief supplies.

India has dispatched three Navy ships with supplies and other aid, the first of which arrived in Colombo on Saturday.

Officials said deaths were reported from the western coastal district of Kalutara, the central southern district of Ratnapura and the southern district of Matara.