A group of robbers barged into the bungalow of the manager of a tea estate in the Islampur subdivision of North Dinajpur early on Tuesday morning, held his family at gunpoint and decamped with cash and gold.

The robbers also fired at the manager’s 16-year-old son who is under treatment at a private nursing home in critical condition. The attackers have ransacked the garden’s office after overpowering the night guard.

Sources said four armed men had entered the T.N. Chowdhury Tea Estate at Bijbari around 2.30am, gone to the office and attacked night guard Biplab Ghosh.

The attackers, sources said, had also locked up the quarters of assistant managers and other employees, before reaching the bungalow of Amrit Khati, the manager.

They broke inside and held the manager and his wife at gunpoint.

“I was in deep sleep and suddenly felt some people had entered the bungalow. They were carrying firearms and threatening to kill my son, daughter-in-law and grandson. We felt intimidated and handed them gold, cash and other valuables. Ashmit, my grandson, tried to prevent them and immediately, they fired at him. They ran away then,” said Madhumaya Khati, the manager’s mother.

Police suspect local people were involved in the heist.

“This is because they appear to be well aware of the geography of the garden. After overpowering the guard, they did not ask for the direction to the manager’s bungalow or accommodations of other employees. While escaping the spot, they had used a ladder to cross the boundary wall. This means they even knew where the ladder was kept. Also, they have taken away the hard disk of CCTV cameras which seems to be an attempt to prevent us from identifying them,” said a police officer.

Sachin Makkar, the superintendent of police of Islampur police district, said: “We are probing the case. Those who were involved in the attack would be identified soon. Raids have started in some areas.”