The Calgary Police Guns and Gangs Unit has arrested four men in connection with a series of separate violent incidents dating back to October of last year.

All of the incidents involved firearms and police believe they were all targeted attacks.

The first incident happened just after 11:00 p.m. on October 5, 2014. Police say a group of people were told to leave a bar in the 1400 block of 52 Street N.E. after a fight broke out.

The altercation continued outside the bar between two separate groups and escalated when one of the men pulled out a handgun and fired several shots at the other group.

A man was hit in the leg and another patron received minor injuries from flying glass.

Police arrested Ramin Dadkhuda, 26, at the end of October and charged him with multiple weapons offences and two counts of aggravated assault.

Police say the second incident happened when two groups of men met up in the 6700 block of 26 Avenue N.E. on October 23 at about 7:30 p.m.

Two groups in two vehicles pulled up alongside each other and someone inside one of the cars opened fire.

The driver of one of the vehicles was hit in the face and the offenders fled the scene.

Three days later, Amaninder Singh, 22, turned himself in to police. He has been charged with attempted murder, aggravated assault, five counts of failing to company and multiple firearms offences.

The most recent case was on January 1, 2015 in the northeast community of Rundle.

Police were called to a home in the 700 block of Rundleside Drive N.E. at about 11:30 p.m for reports of a drive-by shooting.

Investigators say there were several people inside the home at the time, but no one was injured.

That investigation prompted police to execute a search warrant a few days later on a home in the 7000 block of 80 Avenue N.E.

Officers seized about $1,000 worth of cocaine, $27,000 worth of oxycodone, over $35,000 cash and a loaded handgun with a defaced serial number.

Two men, Abdullah Amer, 20, and Azad Ahmed Haji, 28, were arrested at the home and are now facing firearms and drug charges.

Sgt. Jason Walker from the CPS Guns & Gangs Unit says the incidents are not connected but they are still looking to see if they are related in any way. "There's been a few recently and we are aware of that. But the nature, the context, and the connections between them is something that we're actively looking at."

Walker says the violence is likely connected to friction between groups involved in organized crime and the drug trade. "Our job is now to find out which ones are and which ones aren't. They are some that we've removed from the equation, but that's all something we've got going forward."

He says his team works closely with the Homicide Unit on suppression efforts.

"What we don't talk about frequently is the suppression work that goes on behind the scenes. The reason why I can stand here and share investigative success and the reason why we can move forward and prevent future acts of violence is the cooperation from the public which helps us do these things and make those kinds of connections."

Police are asking anyone who knows anything about the incidents to contact them.

For more information on the CPS Guns and Gangs Unit, their activities, and to report issues, go to cpsgrip.com.