Dhubri/ Alipurduar, Oct. 27: A bus with at least 50 people on board was set ablaze in Assam’s Dhubri district shortly after midnight last night. The arson is suspected to be the handiwork of a students’ union that has imposed a blockade on National Highway 31 (C) for the past 10 days.

While 22 passengers suffered burn injuries, three of them are critical. The bus, with 48 passengers on board, was attacked at Nandipara Tiniali under Golokganj police station of Dhubri district around 12.30am.

The arsonists beat up the staff and passengers and then jammed the bus doors from outside before setting the vehicle ablaze. They also hurled a crude petrol bomb to force the driver to stop the bus on the highway.

The needle of suspicion pointed to the Biswajit faction of the All Koch Rajbongshi Students Union (Akrsu), which has imposed a 300-hour-long national highway blockade from October 17 to 29.

The union is demanding a separate Kamtapur state and inclusion of the Koch Rajbongshis in the list of Scheduled Tribes.

All the passengers who sustained burn injuries were taken to Dhubri Civil Hospital. Two children and three women were among those seriously injured. Twenty-six persons were released after first aid, while 14 were shifted to MJN Hospital at Cooch Behar this afternoon.

Bus driver Moksed Ali and conductor Mohan Yadav, who were critically wounded, were today shifted to Gauhati Medical College and Hospital.

Residents of the nearby Charalia village rushed out of their homes on hearing the passengers scream for help. “I broke open a window to help a woman get out from the rear of the bus,” a local resident said.

Golokganj police station sent a team to rescue the passengers. A fire tender from Dhubri was also rushed to the spot.

Bus conductor Ajit Ghosh said from his hospital bed in Cooch Behar: “Around 12.30am, our driver saw a concrete pillar on the road. As soon as the bus stopped, a group of young boys entered the bus, beat us up and poured kerosene on the bus to set it on fire.”

Officer-in-charge of Golokganj police station, Kamal Chandra Sil, said the Assam State Transport Corporation bus ignored a police signal to wait at Chagolia checkgate and proceeded unescorted. “The bus, which left Cooch Be-har for North Lakhimpur via Guwahati around 9.30pm, did not wait for the police escort to arrive at Chagolia,” he said.

Dhubri superintendent of police Partho Sarothi Mahapatro said over telephone: “We have already arrested 14 Akrsu activists and are looking for the other members.”

It has launched a hunt to arrest the union’s president Biswajit Roy and other functionaries of its central committee.