Brawling downtown bar patrons turned their anger on police Monday night in a violent altercation around closing time.
Earlier in the evening, a brawl had broken out on de la Montagne south of Ste-Catherine, prompting 911 calls.
Things had calmed down by the time officers arrived but the patrons got rowdy a few minutes later, and this time they began attacking officers.
People threw bottles and rocks at officers, striking one of them in the head.
The office was transported to hospital - his life is not in danger.
The officers called for backup and it took more than an hour to get things under control.
Two men and a woman were arrested and could face charges of armed assault against a police officer, we well as obstruction.