Mathura, June 2 (IANS) : A police sub-inspector was shot dead and six other policemen, including a superintendent of police, suffered bullet injuries on Thursday during an anti-encroachment drive in Uttar Pradesh's Mathura town, police said.

Farha Station House Officer (SHO) Santosh Kumar Yadav was killed on the spot as the encroachers -- said to be followers of a religious sect -- fired at police who had gone to clear encroachments in Jawaharnagar locality.

Superintendent of Police (City) Mukul Dwivedi and five other policemen were injured. Earlier report said the area Circle Officer was among the injured.

The encroachers threw hand-grenades and bombs at the police and beat up many of them. The number of casualties among the sqatters is still not known.

Soon after the shooting, a mob went on a rampage and some unruly elements took over the collectorate premises.

Mathura Superintendent of Police Rakesh Singh said criminal elements had encroached upon a major part of the 280-acre government land named Jawahar Bagh.

The district administration had announced some time back that the land will be made free of encroachments soon.

The situation continues to be tense in the area and police and paramilitary reinforcements have been rushed there, an official told IANS.

Meanwhile, Uttar Pradesh Chief Minister Akhilesh Yadav announced Rs 20 lakh ex gratia to the family of the killed police official.