At least 48 people were killed and more than 144,000 people affected by flash floods in Kenya, destroying key infrastructure and livelihoods in the East African nation, the United Nations said on Thursday.

The UN Office for Coordination of Humanitarian Affairs (OCHA) which cited figures from the Kenya Red Cross Society said the flash floods, mudslides and landslides were driven by the heavy rains in at least 25 counties.

"The government's National Disaster Operation Centre (NDOC) confirmed that at least 17,000 people have been displaced", OCHA said in its latest update on floods.

The NDOC expects these numbers to rise with the current weather forecasts, which predict heavy rains until the end of November, including affecting 200,000 refugees living in settlements in Dadaab in northeast Kenya.

According to the report, sharp increases on food and fuel prices due to shortages have been reported in Mandera, parts of Wajir and Marsabit counties in northern Kenya, hindering access to food for the most vulnerable.

The heavy rains follow a period of prolonged drought which saw the number of severely food insecure people in Kenya rise to 3.1 million.

The destruction of crucial livelihoods, including an undetermined acreage of farmland and livestock, according to NDOC, will likely heavily impact the food security situation across the country.

"Although the government is still carrying out assessments to determine the extension of damages, there are already several reports of key infrastructure, including roads, bridges, schools and health facilities, destroyed in multiple locations," said the UN agency.

It said roads have been cut off in at least eight counties, paralyzing transport and hampering humanitarian assistance in Mandera, Wajir, Marsabit, Turkana, Garissa, Lamu, Kwale and Mombasa.