A multi-story building under construction in the Kenyan capital, Nairobi, collapsed Friday, leaving an unknown number of people trapped.

Axar.az informs, citing AP, rescue workers are digging through the rubble. The building was in an area of Nairobi known as South C, according to the Kenya Red Cross, and local media say it was a 16-story structure.

“A multi-agency response team is on site managing the situation,” the Kenya Red Cross said in a statement.

There was no immediate comment from authorities on the likely cause of the collapse or the number of victims. The toll is not expected to be high.