At least two people were killed and more were trapped on Sunday after a seven-story unfinished building collapsed in Nigeria’s commercial capital Lagos, rescue authorities said.

Building collapses are common in Africa’s most populous nation where many reside in dilapidated structures and construction safety regulations are often ignored.

The seven-story building collapsed in a commercial area of Lagos, with the structure almost completely flattened, according to photographs released by rescue officials.

Two bodies had been recovered from the rubble on Sunday, Ibrahim Farinloye of the National Emergency Management Agency (NEMA) told AFP by text.

At least four other people were believed trapped inside, and operations were ongoing, local rescue authorities said.

No reason was given for the collapse.

Enforcement of safety regulations and the use of shoddy materials have been highlighted since November last year after a high-rise building under construction collapsed in the Ikoyi district of Lagos, killing at least 45 people.

Ten people were killed when a three-story building collapsed in the Ebute-Metta area of Lagos in May this year.

In January, three people, including two children, were killed and another 18 rescued when a church collapsed in southern Delta state.

Nigerian President Muhammadu Buhari has called for improved construction standards, calling the frequency of building collapses “increasingly embarrassing”.

Since 2005, at least 152 buildings have collapsed in Lagos, according to a South African university researcher investigating construction disasters.

Bad workmanship, low-quality materials, and corruption to bypass official oversight are often blamed for Nigerian building disasters.