The head of Kenya's Red Cross Society says at least 21 people have drowned in floods that have washed over parts of Kenya in the past two weeks.

Abbas Gullet says up to 30,000 people need tents, mosquito nets, water purifying tablets and other aid. He says that number may rise because heavy rains are expected through the end of January.

The Kenya Red Cross Society is worried it will not be able to deliver aid because the flooding has destroyed some roads.

Floods are not common this time of year in Kenya. Meteorologists have blamed the unusual heavy rains on El Nino. El Nino is a periodic warming of the water in the tropical Pacific Ocean accompanied by changes in air pressure and winds that can affect weather worldwide.