An ISIS suspect was killed after an 11-hour-long anti-terror operation in Uttar Pradesh.

The ISIS operative was killed in the early hours of Wednesday after an operation was conducted by the Uttar Pradesh Police's Anti-Terror Squad (ATS) commandos.

Efforts to persuade the suspect to surrender went in vain, according to an official.

The suspect was holed up in a house in Haji colony of Thakurganj area.

The anti-terror forces attacked his location, with the ATS commandos lobbing chilly bombs inside the house to incapacitate him, but the initial exchange of fire was ineffective.

Then the police bored a hole in the roof and blew up the back wall of the building in order to enter the house.

At the beginning of the operation, it was suspected that there were two ISIS operatives inside the house but then that turned out to be a false alarm as police found the body of only one person.

Top police officials were present at the site to oversee the anti-terror operation, and the Union Home Ministry was also monitoring the operation.

"We got a lead on these operatives from outside the state and we are on the trail," said Additional Director General (Law and Order) Daljeet Chowdhary.