Bangladesh was observing a day of national mourning Tuesday as the death toll from a military jet crash on a school compound climbed to 31 and hundreds of students rallied near the crash site demanding accountability.

Firefighters further secured the site in Dhaka’s densely populated Uttara neighborhood while the military launched an investigation. The country’s civil aviation authority was not directly involved in the investigation.

Monday’s crash at the Milestone School and College caused a fire that gutted the two-story school building. Officials said 171 people, mostly students and many with burns, were rescued and carried away in helicopters, ambulances, motorized rickshaws and in the arms of firefighters and parents.

The protesting students demanded "accurate" publication of identities of the dead and injured, compensation for their families and an immediate halt to the use of "outdated and unsafe" training aircraft by the Bangladesh air force.

They chanted slogans and accused security officials of beating them and manhandling teachers on Monday.