A policeman was injured after a mentally-challenged youth attacked him with a knife in Sadar upazila of Brahmanbaria on Sunday afternoon.
Police arrested the attacker Saidul, son of Fazlul Haque in Behair village of Natai North Union of the upazila from the spot.
The injured police officer was identified as Atiqullah, Sub Inspector (SI) of Sadar Model Police Station.
Md Shakhawat Hossain, superintendent of Brahmanbaria police said Saidul locked his mother and father in a room and tried to set the house on fire. After receiving a 999 call, a police team along with the fire service went to the spot and rescued the confined mother and father. Later, when police tried to arrest Saidul, he stabbed SI Atiqullah with the knife, leaving him seriously injured.
At one stage, police managed to take the knife from Saidul and caught him , he added.
Police officer Atiqullah was taken to Sadar Hospital and given first aid.
As his condition deteriorated, the doctor referred him to Dhaka for better treatment.
Later, a helicopter from Rab took him to Dhaka in critical condition at 8:30 pm.