Four suspected aides of Khalistan sympathiser and radical preacher Amritpal Singh who were picked up during a crackdown by Punjab police on Saturday have been brought to Dibrugarh central jail.

An official told The Telegraph that the four arrested persons were flown in on a special IAF aircraft on Sunday morning to Dibrugarh and were taken to the central jail in the Upper Assam town.

The arrested persons were accompanied by a 27-member team from Punjab, including a prison official, which left in the afternoon after completing official procedures.

Around 78 people were arrested in the Punjab police crackdown launched on Saturday.

Asked why the four persons were shifted to Dibrugarh jail, the official said one reason could be safety.

Asked if Amritpal was among them, he said: “Have not been informed about him.”

The identity of the quartet and other details have not been divulged, but security deployment in and around the jail was increased and a metal detector installed at its entry gate on Sunday morning.

Assam chief minister Himanta Biswa Sarma told the media that it was police-to-police cooperation.

The Dibrugarh central jail was established in 1959.

Members of Amritpal’s Waris Punjab De, formed last year, clashed with the police in Punjab on February 23 to get one of his aides released from the Ajnala police station.

Visuals of the attack on the police station left the security establishment worried while reviving memories of the militancy in support of Khalistan that rocked Punjab from the mid-eighties to the mid-nineties.

Amritpal had last month said the Khalistani movement could not be stopped from flourishing.