The robbers stabbed UNDP Programme Officer Soumitra Kumar Dev, 35, and three others including the driver and supervisor of the bus. Soumitra later died in hospital.

The three robbers died of mob beating and four of their cohorts were arrested as they were attempting to run off in a getaway microbus after looting the bus passengers.

Police said a gang of eight armed robbers in the guise of passengers took the driver and the supervisor of the Dhaka-bound night coach from Rangpur hostage around 8:30pm. The robbers stabbed the four as they tried to resist them.

After looting the bus passengers at gunpoint, the robbers got down at Karatia Bypass and went towards Delduar through Tangail town in a microbus.

Soumitra, Mujibur Rahman, 32, bus driver Jhikrul Haque, 38, and supervisor of the bus Pathik alias Faruque, 26, were rushed to Mirzapur Kumudini Hospital where Soumitra succumbed to his injuries.

Being informed a police team chased the microbus and finally caught up with it at Bhurbhuria in Delduar upazila around 10:00pm.

Locals captured three of the robbers and beat them up as they were trying to flee getting down from the microbus. One robber died instantly while the other two critically injured in the beating died around midnight.

The dead robbers were identified as Salim, 32, Guljar Hossain alias Rabiul, 45, and Aslam, 30.

Police later arrested four out of the five remaining robbers in a paddy field in the area.

The arrested robbers are Azizul Ali, 20, Milon Haoladar, 30, Abdus Subahan, 42, and Selim Sheikh, 32.

Police seized the microbus and recovered all looted valuables.

Bodies of the three dead robbers were sent to Tangail General Hospital morgue for autopsy.

Police sources said the arrested robbers told police during interrogation that they rented the microbus from a car rental company in the capital on Thursday and went to Rangpur the same day.