Hundreds of students gathered outside the smoldering 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.

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.

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.