NAIROBI, Kenya (AP) — A building collapsed during a planned demolition that went wrong Monday in the Kenyan capital of Nairobi, killing at least four people and injuring four others, officials said.

Rescue workers from the army and other institutions were working to find any people trapped under the rubble, the Interior Ministry said in a statement. Images showed victims being carried away from the rubble on stretchers.

It wasn’t immediately clear what happened during the demolition that led to the deaths and injuries.

The building had been one of several “earmarked for removal under the ongoing Nairobi River Regeneration Project,” the statement said.

At least two people were rescued, but an Associated Press journalist at the scene in the Blue Estate community of Shauri Moyo counted at least three bodies pulled from the collapsed structure. The Interior Ministry put the death toll at four.

Building collapses are common in Nairobi, where housing is in high demand and unscrupulous developers often bypass regulations or simply violate building codes.

After eight buildings collapsed and killed 15 people in Kenya in 2015, the presidency ordered an audit of buildings across the country to see if they were up to code. The National Construction Authority found that 58% of the buildings in Nairobi were unfit for habitation.