A Bangladeshi military training aircraft crashed into the campus of a school in Dhaka, killing the pilot and at least 19 others, mostly students, officials say.

Hundreds of students gathered outside the smouldering remains of a school in the Bangladeshi capital on Tuesday to demand answers after a military jet slammed into the campus, killing dozens of children.

At least 27 people were killed after a Bangladesh Air Force training aircraft crashed into the premises of Milestone School and College in Dhaka on Monday, triggering widespread panic and outrage among students and residents in the densely populated area.