Floods in north Nigeria have killed more than 80% of animals in a large zoo with an array of wildlife from lions and crocodiles to buffaloes and ostriches, the facility said on Tuesday.

"Some deadly animals have been washed away into our communities, like crocodiles and snakes," Sanda Kyarimi Park Zoo added in a statement on the floods in northern Borno state, urging residents to take precautions.

Floods began when a dam overflowed following heavy rains, uprooting thousands of people.

The disaster has affected other facilities in the state capital Maiduguri including the post office and a teaching hospital, Nigerian President Bola Tinubu's office said, telling people to evacuate worst-hit areas.

"President Tinubu extends his heartfelt condolences to the government and people of the state, especially to the families that have lost their means of livelihood due to the disaster triggered by the overflow of the Alau Dam," the statement said, saying humanitarian needs would be addressed.

Floods in the northeast killed at least 49 people last month, while a 2022 flood killed more than 600.

Borno state, the birthplace of Boko Haram, is already grappling with a 15-year insurgency that has killed and displaced many.