Thousands of people paid tribute  Thursday to the 61 people killed last month when a makeshift dam ruptured in central Kenya, following heavy rains that have plunged the country into turmoil.

The tragedy near the Rift Valley town of Mai Mahiu was the deadliest single incident during a particularly brutal rainy season that has claimed 257 lives and displaced almost 55,000 households since March in the East African nation.

The disaster struck before dawn on April 29, when torrential downpours burst the dam, sending torrents of water and mud gushing down a hill.

The deluge cut off a road and washed away homes, devastating the village of Kamuchiri and killing 61, according to local MP Jane Kihara.

Thousands of people -- victims' relatives, residents as well as political leaders -- gathered to honour the dead in Mai Mahiu, a few kilometres from the scene of the tragedy.

Under a large tent, dozens of portraits of victims, including many children, were exhibited in front of flowers and candles, an AFP journalist at the scene said.

An emotional crowd listened to speeches by religious and political leaders, including Deputy President Rigathi Gachagua who read a message from President William Ruto.

"In these difficult times, we stand in solidarity with those who have been affected by the disaster," he said.

The government warned on Wednesday that heavy rains were expected in 31 of Kenya's 47 counties.

Water levels of Lake Victoria -- the largest in Africa -- and Lake Baringo are expected to continue to rise, raising the threat of further flooding.

The authorities have also warned that all five dams comprising the Seven Forks hydropower project pose "an increased risk of flooding" in the counties of Garissa, Tana River and Lamu located downstream.

A total of 192 dams have been identified as "high risk" and populations living near 178 of them have been evacuated, according to the government.

The rains have also battered the rest of East Africa, compounded by the El Nino weather pattern.

At least 475 people have died in Kenya, Tanzania, Burundi, Rwanda, Uganda, Ethiopia, and Somalia, according to government data and  figures from the UN humanitarian agency OCHA compiled by AFP.