At least six people were killed and 23 injured when strong winds and heavy rains lashed Sri Lanka since Wednesday night, prompting authorities to issue a severe weather alert, Xinxua reported.
The Disaster Management Center said the fatalities had been reported from Galle, Gampaha and Badulla Districts while severe destruction had been caused in several areas across the country.
The center said since water levels in some of the major rivers, including Nilwala, Gin and Kalu rivers, were rising due to heavy rains, people had been urged to move to higher grounds.
The police and relief teams had been advised to be on alert and help those who had been stranded or affected by the adverse weather.
The Meteorology Department said in its latest weather forecast that more heavy rains and gusty strong winds could be expected over the island, and heavy rains, strong winds and rough seas could also be expected further in the deep and shallow sea areas around the island too.
The department warned fishermen against going to sea.
"The depression in the south-west of Sri Lanka has developed into a deep depression and it is located 200 km away from Colombo. It is expected to develop further and move to the Arabian Sea area," the weather forecast said.
The Disaster Management Center also dismissed rumors of a tsunami threat to the island, which had spread panic among those living in the coastal areas.
Heavy rain falls about 100 to 150 mm could be expected at some places in the Southern, Sabaragamuwa, Central, Western and Uva provinces.
President Maithripala Sirisena on Thursday ordered Sri Lankan forces to provide immediate assistance to those affected by the disaster.
The president's office said that Sirisena, who is on a visit to South Korea, had been briefed on the situation by the Disaster Management Center.
The government has also announced that an immediate sum of 10,000 rupees (65.2 U.S. dollars) would be given to each family affected by the adverse weather.
Meanwhile, rail services were delayed in many areas due to fallen trees across railway tracks and landslide warnings. People had been urged to stay indoors.
Several houses were damaged and trees had been uprooted in several areas, making roads inaccessible. Authorities had begun clean up operations amid heavy rains.
Schools were closed in the Western, Southern, Uva and Central Provinces on Wednesday owing to the adverse weather conditions.