At least 13 people died in Rwanda's capital, Kigali, in overnight heavy rains that also left others injured, AP reports quoting a government official.

The heavy downpour began on Sunday evening, causing floods and mudslides that swept away 15 houses and blocked some roads.

"We can confirm that the provisional number of those dead has reached 13. Some people who we thought were missing have been found dead and the search continues," AP quotes Claude Tuyishime, spokesman of the ministry of disaster management.

The latest deaths come just days after three people were killed in another heavy downpour which destroyed farms and swept away homes. In December, 12 other people were killed in Kigali while officials said more than 100 homes were destroyed.

The government has started relocating thousands of households that reside in wetlands and other at-risk areas.

The Rwanda Meteorology Agency says more rains are still expected.