At least 30 people have been killed in the Nijeria’s floods, officials said. However, the death toll is likely to rise as authorities are still scrambling to rescue thousands of others feared trapped in their homes.

Devastating floods in northeastern Nigeria have submerged entire residential areas, displaced tens of thousands of people, and forced zoo animals to escape into the streets.

The floods hit Borno State early this week after a dam impounding a regional river burst its banks. The heavy surge of water buried half the state capital, Maiduguri, damaging buildings and infrastructure.

Authorities say some one million people are affected, of which about 200,000 are displaced.

Floods are not uncommon in northern Nigeria. However, experts say Maiduguri is seeing its worst flood in 30 years.