Jail sources said a group of inmates led by 'Kangali' Zakir, a convict in Police Sergeant Ahad murder case, on Monday morning assaulted its rival group headed by Emran, an associate of dreaded criminal 'Sweden' Aslam, in an alleged bid to establish control over drug trading in the jail.

Armed with razor blades, the Zakir group again attacked Emran and his group yesterday morning when they were going to lodge a complaint against 'Kangali' Zakir with the jail authorities.

At least 10 operatives of 'Sweden' Aslam were injured in the clash.

Soon after the morning's clash, some jail guards searched Masum, an accused in the BUET student Sabekunnesa Sony murder case, suspecting he had some drugs on him, but found nothing.

When the jail guards attempted to search Masum again, notorious criminal 'Pichchi' Helal opposed the move, locking in an altercation with them. Helal, at one stage, assaulted them, sparking off a scuffle between the jailers and the inmates.

A number of more jail guards joined in with their colleagues and mercilessly beat up the feuding inmates, leaving some of them seriously injured.

As the wounded were not provided with treatment, 'Pichchi' Helal and his associates launched a hunger strike in their cell No. 10 yesterday noon.

Senior prison officials later met with the striking prisoners and brought normalcy back in the jail. Six critically wounded inmates were admitted to different city hospitals including the one in the jail.

Despite repeated attempts last night, the inspector general of prisons and the jail super could not be reached.

However, a top jail official acknowledged the incidents seeking anonymity. He also admitted to have stand-released six guards for violating the jail codes.