Rescuers in Nigeria scrambled to find survivors on Wednesday, two days after a high-rise building under construction in the commercial city Lagos collapsed and trapped scores of people, raising the dead toll to 22, according to an emergency official.

Anxious family members and big groups gathered near the accident scene, hoping to learn more about the fate of people still trapped beneath masonry and shredded steel where the building previously stood.

National Emergency Management Agency coordinator for Lagos Ibrahim Farinloye told Reuters via text message that the death toll had climbed to 22 after several bodies were recovered overnight. Nine people were pulled out alive.

Building collapses are frequent in Africa’s most populous country, where regulations are poorly enforced and construction materials often substandard.

The Lagos state government said there had been some building infractions during construction earlier this year but did not say whether these had been rectified.

The state’s chief architect was on Tuesday suspended indefinitely as the government launched an independent investigation into the causes of the collapse of what was planned to be a high-end apartment block. The results of the probe will be made public.