06/22/2017 09:01 EDT | Updated 06/22/2017 19:23 EDT

Men hit over back of head: Man charged in one of 3 attacks in downtown Calgary

CALGARY — Police have charged a man with aggravated assault in the first of three attacks in downtown Calgary in which men were hit in the back of the head with heavy objects.

A man was taken to hospital in life-threatening condition after the initial attack on Saturday, but was upgraded to stable a few days later.

A second man was also seriously hurt when he was hit with a piece of concrete early Monday while he was using a pay phone outside a Safeway store.

A third man was taken to hospital when patrol officers found him unconscious at about 4 a.m. Tuesday.

Jason McKenzie, 29, was charged Thursday.

Police say they are not looking for any other suspects.

Investigators had asked the public to help them identify a man caught on a security camera at the site of one of the attacks.

They also said the victims weren't believed to be connected to each other, but it was not known if they had some prior involvement with their attacker before the assaults.