At least four people are feared trapped in rubble after a four-story building collapsed near the Kenyan capital Nairobi, officials say.

Joseph Gichangi, the police chief of the Ruai area, said a watchman who left the building, a guest house, shortly before it collapsed reported four guests inside.

Kenya’s military is leading rescue operations.

Building collapses have become common in Nairobi, where four million people live in low-income areas or slums.

Housing is in high demand and unscrupulous developers often bypass regulations.

After eight buildings collapsed and killed 15 people in Kenya in 2015, President Uhuru Kenyatta ordered an audit of all the country’s buildings to see if they were up to standard.

The National Construction Authority found 58% of buildings in Nairobi were unfit for habitation.