Story highlights

The rains triggered a flood that washed away houses

Thirty-five people are missing

Search-and-rescue operations are under way

(CNN) —  

Heavy rains in central Nigeria triggered a flood that washed away houses and killed at least 21 people, government officials said Monday.

Another 35 people are missing, according to the National Emergency Management Agency.

Search-and-rescue operations are under way in the Gangare and Rikkos areas of Jos, a city in central Nigeria, the agency said. The river that cuts through Rikkos overflowed, flooding nearby homes, it added.

It said two shelters were opened at schools to help those displaced by the water.

Rain in central Nigeria is not uncommon for this time of year, but it has been unusually heavy in the past week.

CNN’s Vlad Duthiers and journalist Hassan John contributed to this report.