Patna/Ara: Inmates and security personnel were injured on Saturday when a clash broke out between two groups of prisoners at Ara district jail, close on the heels of a video from the jail going viral on social networking sites.

An undertrial and a jail warder were rushed to Ara sadar hospital for treatment, while the others were treated at the hospital inside the prison, around 60km west of Patna.

A joint team of Bhojpur district and police administration had raided the jail on Friday after a video showing a group of inmates smoking ganja and talking over mobile phones went viral.

Saturday's trouble started around 9am after two prisoners got into a disagreement. Supporters of the two rivals attacked each other, injuring at least six inmates. A warder, assigned to maintain law and order inside the jail, was assaulted by the warring groups when he tried to intervene.

The prisoners also made an abortive attempt to break open the jail's main entrance, prompting the security personnel to baton charge them. Ara sadar sub-divisional officer Arun Prakash and sub-divisional police officer Sanjay Kumar also rushed to the jail with reinforcements.

Sources said the prisoners were agitated over the viral video. A section of the prisoners accused another group of circulating the video, drawing the attention of the district administration to the jail. The situation was brought under control after Arun and Sanjay intervened.

Friday's viral video was not an isolated case. Two groups, led by Bablu Tatwa of Ara and Butan Choudhary of Belaur in Bhojpur, had clashed at the jail on May 8 last year.

Bhojpur superintendent of police Avakash Kumar said the video that went viral on Friday looked to be at least one-and-a-half-year old and inmates who were out on bail had posted it on the social networking sites.

The police have ordered an investigation into the incident, Avakash said, adding that a report had been sought from jail superintendent Niranjan Pandit within 24 hours. "We are investigating how cellphones, ganja (marijuana) and other drugs reached the jail," he told The Telegraph over phone.