All told, 16 inmates refused to return to their cells within the walls of the St. Francois St. clink.

The standoff began at about 9:30 a.m.

Members of the Surete du Quebec and Gatineau Police sealed off the scene, followed by a team from Montreal and a police negotiator.

No prison guards were injured and there were no reports of any other violence, SQ spokesman Sgt. Marc Tessier said.

"We're trying to communicate with them to determine what they want," said Tessier early in the day. "There is contact with the detainees."

It wasn't known if the inmates are armed, but they had access to cell items, some of which could be transformed into crude weapons with some ingenuity.

With the lockdown in place, the barricaded bunch was confined to the maximum security wing, which is separate from the rest of the jail.

Ordinary inmates were also under lockdown.

The standoff ended around 6:30 p.m.