According to police, they had got information that some persons were illegally carrying sand in tractor-trolleys from Jahargaon in Chambal Ghadiyal sanctuary area under Saray Chhola police station this morning.
Following the tip-off, police managed to seize one of the tractor-trolleys and arrested its driver.
However, after some time members of the sand mafia came to the spot in large numbers and attacked the police with stones before fleeing away with the seized vehicle, they said, adding Saray Chhola police station in-charge P N Pal was injured in the incident.
Although eyewitnesses claimed that police had opened fire in the air to resist the attackers, police denied doing so.
SP Sanjay Kumar Singh said the sand mafia members could escape because there were only a few police personnel at the site. He, however, said that those involved in the incident would be nabbed soon.