The clash ensued when Rab men plying on a training bus beat a driver of Soukhin Paribahan on the Dhaka-Mymensingh Highway in the morning.

Witnesses said 13 Rab members of the headquarters reached Bagher Bazar area from Naljani of the district on a Bangladesh Road Transport and Corporation (BRTC) training bus at around 9:00am, where one side of the road was closed due to repair work.

The driver of the bus carrying Rab men entered into the single-lane where another bus of Soukhin Paribahanhad already coming through created a huge traffic jam at Bagher Bazar bus stand, said witnesses.

"As one side of the highway was closed due to repair work of the road, the vehicles were passing through another side," local police sources said. "When the Rab vehicle tried to cross the area, ignoring the passenger bus, the road got blocked as both the vehicles came face to face, occupying the entire space," he said.

Both the drivers asked the other to move back but none agreed, and the two locked in an altercation. At one point, the BRTC driver beat the driver of the passenger-carrying bus and the Rab men joined them, said witnesses.

The passengers and the locals became agitated and attacked the BRTC bus with sticks, iron-rods and bricks.

Seeing the situation, the Rab members, who were in plainclothes, identified themselves, which angered the locals more. They vandalised the bus and beat the Rab members, who also fought against the locals.

At least 15 people were injured during the battle, including four Rab members sepoys Kamal, Murad, Monju and Nazrul, who were admitted to the Combined Military Hospital at Rajendrapur.

Sepoy Kamal was injured under the left eye, Murad had a fracture in the right hand while Manju received injuries in the neck.

Hearing the news, a contingent of Joydevpur police and Rab officials from its headquarters at Uttara rushed to the spot and brought the situation under control.

Panic gripped the area until evening as the Rab members were patrolling the locality after the incident. Youths of the area left their houses to avoid arrest and torture by the Rab, police sources said.

Operation Instructor Nazrul Islam of BRTC filed a case with Joydebpur Police Station, said Second Officer Badrul Alam Talukdar.

Joydevpur police admitted the incident, saying that RAB was preparing to lodge a case against the unruly people of the area.