Chinsurah, Aug. 20: A group of Trinamul supporters led by a councillor of Serampore municipality today locked a BSNL office with several employees inside.

The trigger: the telecom comapany's failure to pull down one of its unused buildings that apparently poses a threat to an adjacent ward office building.

BSNL runs a telephone exchange on Dey Street in Ward 13 and the three-storey condemned building was used in the past as staff quarters.

Chunks of concrete from the building keep falling on the ward office, Trinamul councillor Jhum Mukherjee claimed. Repeated pleas to BSNL authorities to raze the building have had no effect, she said.

The employees remained locked for over an hour till cops arrived and unlocked the office.

Police claimed BSNL authorities will start the demolition work from Monday.