Among the injured, one is identified as Presiding Officer Mahmudul Hasan, the upazila family planning officer.
The incident took place at Nateswar union’s Maddhya Nateswar Ebtedayii Nurani Madrasa polling centre around 10:30 pm, said Elias Faruque, superintendent of Noakhali police.
Being informed about the attack, a team from Sonaimuri police station rushed in and fired several rounds of gunshots on the air to disperse the attackers, he said.
Police were conducting drives to recover the election materials till filling of this report around 0030 am, said the police super.
After rescuing four injured including Mahmudul, police took them to Noakhali General Hospital.
Meanwhile, Mahmudul was sent to Dhaka by an ambulance as his condition was critical, he said.