Monsoon rains and strong winds in Sri Lanka have killed at least 19 people with dozens more missing, most of them fishermen caught in rough seas, officials said.

The bodies of 18 fishermen have so far been found, while the body of another person was discovered on land, Sarath Kumara Gunaratne, deputy minister of disaster management, told reporters on Sunday.

The navy and airforce were searching for 36 fishermen who have been missing at sea since the monsoon hit early on Saturday, the minister said. 

"The navy and the airforce have deployed several craft to look for survivors. At least 21 injured fishermen have been rescued so far and admitted to hospital," he said.

Heavy showers were expected in many parts of the island on Sunday with winds already reaching speeds of over 70 kilometres per hour, a meteorological office said.

Source: Agencies