The police closed down Monir Filling Station at Kazipara in Mirpur and arrested four employees -- Shahadat, Jahid, Tanjir and Akash -- on charges of fraud. However, the owner, Gausuddin Khan, has gone into hiding.

A case has been filed with Mirpur Police Station.

About 25 buses and trucks in the early hours yesterday refuelled from the filling station, but after driving a kilometre or two the vehicles came to a stop.

On suspicion, the drivers ran a test on whether the 'fuel' lights, but it did not, police quoted one of the drivers, Didar Alam, as telling them. The drivers then informed Mirpur police of the matter.

The investigation officer of the case, Shajahan Miah of Mirpur police, said many drivers have complained to him that the filling station has been selling adulterated fuel for long.

The police have sent the arrestees to court with a five-day remand prayer for each of them.