A primary school building has collapsed in the Nigerian city of Lagos, leaving school students trapped under the rubble.

Up to 100 students reportedly attended the school, with emergency management officials saying the current number of fatalities remains unknown.

Crews have pulled around 40 people from the 3 storey building which collapsed around 10am local time on Wednesday morning according to a spokesman for Nigeria’s National Emergency Management Agency.

Building collapses are not uncommon in Nigeria due to unenforced construction standards, with a church that collapsed in 2016 killing 100 people.