Patna, Dec. 17: Onkar Nath Singh alias Sheru Singh, a 25-year-old undertrial prisoner facing charges of murder and extortion, escaped from the civil court premises in Buxar town after shooting at a police constable this afternoon.

The injured constable, Md. Shamim Akhter, has been admitted to the sadar hospital where his condition is stated to be critical.

Sheru, named in over a dozen cases of murder and extortion, was arrested along with his associate Chandan Mishra in September this year from Dharamtalla area in central Calcutta.

He had gone to the city to extort money from a Bihar-based businessman.

On September 8, a Bihar police team, with help from Calcutta police, raided the Dharamtalla area and arrested Sheru and Chandan. The two were subsequently brought to Buxar under tight security arrangements. Sheru was lodged at Buxar central jail.

Buxar sub-divisional police officer Arvind Kumar Gupta said Sheru escaped from the courtroom around 1.30pm. He had been produced in the court in connection with a murder case.

According to sources, Sheru’s aides flung chilli powder at the eyes of the policemen escorting him to the courtroom from the hazat (lock-up). The goons later opened fire causing bullet injuries to Shamim.

The indiscriminate firing triggered panic among the people on the court premises and resulted in a stampede-like situation. Taking advantage of the commotion, Sheru snatched a pistol from a policeman escorting him and fired at Shamim from close range. He escaped on a motorcycle parked for him outside the court premises, eyewitnesses said.

Sheru had unleashed a reign of terror in Buxar after a series of murder of businessmen. He became a dreaded name in the crime world after the murder of businessman Rajendra Prasad Keshari, about three months ago. Keshari was shot in broad daylight at his shop in Buxar town on August 21.

The state government had announced a cash reward of Rs 1 lakh for giving information about the whereabouts of the dreaded contract killer.

Police said Sheru was involved in at least eight cases of murder and five cases of extortion in Buxar district alone. His escape from judicial custody has sent shock waves among the members of the traders’ community, who had become the soft target for Sheru’s gang.

Sheru, a resident of Buxar, allegedly killed his girlfriend’s father three years ago when the latter did not allow him to marry his daughter.

“We apprehend more attacks in the days to come if Sheru is not arrested soon,” said a businessman of Buxar town under cover of anonymity.