A Bangladesh Air Force jet crashed into a college in the capital Dhaka on Monday, killing at least 27 people, mostly children, according to officials – in the country’s deadliest air incident in recent memory.

A Bangladesh Air Force plane has crashed into a college and school campus in Dhaka, killing at least 31 people, including 25 children. The incident on Monday is the deadliest aviation disaster in the Bangladeshi capital in recent memory.

Nearly all of the 31 killed when the plane crashed were children. Dozens more were being treated as the nation declared a day of mourning.