East Africa has been experiencing torrential rains in recent weeks that have cost the lives of at least 58 people in Tanzania in the first half of April, and 13 people in Kenya.

Burundi, which the UN says is one of the 20 countries most vulnerable to climate change, has been pelted by almost non-stop rain since September, with its main city of Bujumbura ravaged by floods.

"The heavy rainfall due to the El Nino phenomenon is causing severe flooding linked to overflowing rivers and the rising waters of Lake Tanganyika. Landslides, strong winds and hail continue to expose communities to different vulnerabilities," Interior Minister Martin Niteretse and UN resident coordinator Violet Kenyana Kakyomya said in a joint statement Tuesday.

Between September and April 7, a total of 203,944 people were affected while the number of internally displaced people increased by 25 percent to 96,000, they said.

The statement referred to a "loss of human life", without giving any further details, adding that homes and livelihoods, crop fields and infrastructure had been destroyed.

The government of President Evariste Ndayishimiye has been under fire for several weeks, particularly from civil society groups and the opposition, which are calling for the authorities to declare a state of emergency or natural disaster.

Usually there are two rainy seasons between September and January and March to May, but the situation has been exacerbated by the El Nino weather phenomenon.

Weather forecasts predict rainfall significantly above normal until May and "the government and humanitarian actors need financial resources to face the growing challenges and avoid a deterioration" of the crisis, the joint statement said.

It said 306,000 people are in need of humanitarian assistance in Burundi, ranked by the World Bank as the poorest country on the planet in terms of per capita GDP.

In the economic capital Bujumbura, which lies on the northeastern shore of Lake Tanganyika, several neighbourhoods have been flooded, roads and bridges destroyed, and some hotels and hospitals abandoned because of rising water levels.

The water level in Africa's second largest lake reached 77.04 metres (over 250 foot) on April 12, just 36 centimetres shy of its 1964 record, disaster prevention agency head Anicet Nibaruta said on Friday, according to Burundian media.

El Nino often has devastating consequences in East Africa, where in December alone, more than 300 people died in torrential rains and floods in Kenya, Somalia and Ethiopia.

From October 1997 to January 1998, massive floods caused more than 6,000 deaths in five countries in the region.