Police used tear gas to disperse angry students in Bangladesh on Tuesday who demanded answers from the interim government after an air force fighter jet crashed into a Dhaka school and killed 31 people, at least 25 of them children, Reuters reported.

The children, many aged under 12, were about to return home from class on Monday when the Chinese-manufactured F-7 BGI Bangladesh Air Force jet ploughed into their school and burst into flames, trapping pupils in the fire and debris.

The military said it had suffered mechanical failure, according to Reuters.

Students from the school and others from nearby colleges protested as two government officials visited the crash site, demanding an accurate death toll and shouting, "Why did our brothers die? We demand answers!"