Police in Kenya have said nine people died after a crane collapsed at a high-rise construction site in Nairobi.

Officer Muturi Mbogo said the crane collapsed on Thursday while it was being dismantled by workers. He said another worker was seriously injured. He said the collapse is under investigation.

A worker at the site, Michael Odhiambo, said the crane fell after its work was completed on the 14th floor.

“It seems they did not realise the nuts tying it were loose,” he said of fellow workers. “We heard a loud bang, only to realise the crane was down.”

Two Chinese engineers were among the victims, Odhiambo said. The project to build a 14-story student hostel is being supervised by a Chinese construction firm.

The Zhejiang Chengjian Construction Africa Ltd said in a statement that it has sealed off the site and is cooperating with police and other authorities.