At least 10 people have died and many more are feared trapped after a building containing a school collapsed in the Nigerian city of Lagos.
The school, which was on the top floor of the four-storey building in Ita Faji on Lagos Island, had more than 100 pupils, a rescue official told the BBC.
About 40 pupils had been pulled out alive, the official said.
The building had been identified as "distressed" and listed for demolition, Lagos building officials told the BBC.
The collapse happened at about 10:00 local time (09:00 GMT). There were frantic scenes at the site as rescuers and local men searched for survivors, and family members crowded the area in the hope of finding their loved ones alive.
The collapsed building was a residential block containing a number of apartments as well as the school, residents and rescue officials at the scene told the BBC.
Emergency teams pulled several injured pupils from the rubble, but many worried parents at the scene were unable to find their children, while others went to a local hospital to look for theirs.
Men from the local area were assisting rescuers but large crowds of people were hindering the rescue operation.
Mohammed Muftau, a local resident who witnessed the collapse, told the BBC that the building had been cracking for long time and that complaints had been raised about it.
The Lagos State Building Control Agency confirmed to the BBC that the building had been marked and listed for demolition. It is not unusual for buildings to collapse in Nigeria; materials are often sub-standard and the enforcement of regulations is lax.
In September 2014, 116 people died when a six-storey building collapsed in Lagos during a service given by a celebrity televangelist. And in 2016, more than 100 people died when the roof of a church in Uyo, in the south of Nigeria, caved in.
At the Lagos Island General Hospital, there was a scene of chaos as parents and family members scrambled after every ambulance that arrived to see if it contained a loved one. Many of the victims brought in were children in school uniforms.
Visiting the hospital, the Lagos state deputy governor, Idiat Oluranti Adebule, offered condolences to the families of the victims and called for calm.
"We plead for their understanding to allow the rescue team to do their work... so that the medical team can take prompt and immediate action as soon as the patients are brought in," she told the BBC.
President Muhammadu Buhari offered his condolences to the families of the victims.
"It touches one to lose precious lives in any kind of mishap, particularly those so young and tender," he said. "May God grant everyone affected by this sad incident fortitude and succour."