At least 12 people have died and more than 40,000 displaced after heavy rains affect much of country.

Heavy monsoon rain in Sri Lanka has left at least 12 people dead and more than 40,000 others displaced across the country.

Officials ordered the military to help those affected by the showers, believed to be upwards of 100,000 people so far.

The country’s disaster management agency has issued alerts warning of the risk of landslides after days of heavy rain.

Al Jazeera’s Minelle Fernandez, reporting from Kalutara in South-Western Sri Lanka, said the Sri Lankan navy was ferrying those in need to hospitals.

“We’re hearing that waters are receding but here in Kalutara…what you see is not a lake, not a reservoir, not a sea, but what used to be paddy fields until the deluge of water over the past couple of days,” our correspondent said.

Sri Lankan officials say the water levels are dropping but warn that more rain is on the way.

May is usually the wettest time of the year in southern and western parts of Sri Lanka, as the summer monsoon sets up across the island.

Last year, the rains in May and June were so heavy that 100 people were killed and hundreds of thousands of others had to seek temporary accommodations.