Twenty-two prisoners locked up for minor misdemeanours are now facing criminal charges for attacking guards and escaping from police custody.

Police are hunting the fugitives, who broke out of holding cells on Thursday night.

They ambushed guards and stole keys which they then used to get out of the station in the suburban Minhang District, police said.

Apparently the prisoners set up a brawl in their cells which distracted two of the guards. When the officers barged into the lock-up to break up the fight, the group grabbed the guards instead, according to the Shanghai Public Security Bureau.

The two guards were injured in the struggle before the 22 fled, the statement said.

Shanghai police are now urging the men to give themselves up in exchange for leniency, and are encouraging people to report anything they may see.

Police have also set up sentry posts all over the city.

The efforts have already started to pay off.

By 5:30 pm on Friday, five of the men had been re-arrested, but 17 were still at large, an official with the Shanghai Public Security Bureau said.

He also said the men were not serious criminals and in fact were only being held for minor offences, which is the purpose of holding cells.

Offences such as group scuffles or harassing women fall under this category.

Police have the authority to impose fines of up to 3,000 yuan (US$363) or keep people in custody for up to 15 days for such transgressions.

Attacking a police officer or escaping from custody are, on the other hand, both considered criminal acts.

Source: China Daily