More than 40 students of Bhuyapara High School under Kachua upazila in Chandpur district have been injured as Jubo League activists attacked them.
Contacted, Ibrahim khalil, officer-in-charge of Kachua police station, confirmed the incident.
On information, police forces were sent to the spot, he said.
Sources said some Jubo League activists went to the school on August 15 and demanded extortion to its headmaster Dulal Chandra Sarker on the occasion of National Mourning Day.
They harassed him physically as he denied giving the extortion.
Fazlur Rahman, an assistant teacher of the school went to the spot and rescued the headmaster. He also protested the Jubo League men.
Later, a number of Jubo League activists attacked the house of Fazlur Rahman at night and tortured him.
On Sunday morning, the students organised a protest rally on the school premises while Jubo League activists led by Faruk, Liton and Munir attacked them with local made firearms, leaving 40 injured.
Of the injured, Sujan, Sahaparan, Rakib, Makbul, Milon, Rafi,Popy, Misti, Tania, Sayema and Tanjina Meem were admitted to hospital in critical condition.