Harjit Singh, an assistant sub inspector with the Punjab Police, was patrolling outside a vegetable market in Patiala when seven men belonging to the Nihang Sikh warrior sect turned violent.

Footage shows a truck ramming through the barricades before the warriors leap from their vehicle and attack with traditional Sikh blades.

Singh's left hand is cut from his wrist and he can be seen writhing on the floor in agony, screaming as he tries to stem the flow of blood with a handkerchief.  

The assailants were arrested and brought into custody, but Singh and six fellow officers suffered injuries and were rushed to the Postgraduate Institute of Medical Education and Research in Chandigarh, according to CNN. 

After more than seven hours of 'painstaking' surgery, doctors managed to reattach Singh's severed limb to his left wrist.

Captain Amarinder Singh of the Punjab Police tweeted: 'Police Party on Naka duty was attacked today in which one ASI's hand was cut off and six were injured.

The assailants were arrested and brought into custody, but Singh and six fellow officers suffered injuries and were rushed to the Postgraduate Institute of Medical Education and Research in Chandigarh, according to CNN. 

After more than seven hours of 'painstaking' surgery, doctors managed to reattach Singh's severed limb to his left wrist.