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.

Hundreds of students protested Tuesday near the site of the crash of a Bangladesh air force training jet into a school in the nation's capital, demanding accountability, compensation for victims' families and the halt of training flights.

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.