Rescue crews pulled nine bodies from the debris of the six-story building that served as headquarters for police detectives.

About 180 people, among them civilians in cells, are believed to have been in the building when it crumbled before dawn on March 29. Officials said the dead included 13 men, 10 women and a baby.

Crews using a crane, bulldozers and sniffer dogs have rescued 145 people. Most of those inside were being held by police investigating criminal activities. The baby was believed to have been with its mother, who was under arrest.

The government says it has opened an official inquiry to find out why the building collapsed.

“We are discounting any external cause” for the collapse, Interior Minister Leal Monteiro Ngongo said. “It's more likely a structural problem”.

The building was built 30 years ago, officials said. Many buildings in the capital of Angola are in a poor state of repair due to the Southwest African country's two-decade civil war, which ended in 2002.