Michael Roberto served a two-year sentence for aggravated assault. (Calgary Police Service)

Calgary police say they've arrested two "significant" gang members on firearms charges — and will work hard to ensure they're not released on bail.

"This is a big deal," said Staff Sgt. Gord Eiriksson on Friday. "We've got two well-known members, not just associates but gang members, who are off the streets and won't be involved in violence either as victims or aggressors … at the very least for the next few days."

As part of an ongoing police campaign to tackle gang violence in the city, officers spotted a GMC Suburban and identified the driver and passenger as "known gang members," according to police.

They attempted to stop the SUV, but it continued driving in the northwest community of Hidden Valley. The passenger was seen to leave the vehicle and discard an object in the median before jumping back into the SUV, said police.

Hans Eastgaard, in an undated photo, was injured in a November gun battle.

A loaded handgun was later found in that same area.

Police managed to stop the vehicle on Beddington Trail where the two men inside, who were both wearing body armour, were arrested.

Michael Joseph Roberto, 25, has been charged with 11 offences, including possession of a prohibited weapon, failure to stop, and being in breach of recognizance.

When Roberto completed a two-year sentence for aggravated assault in 2004, Calgary police issued a public warning that he was a violent offender who had problems with anger management.

Hans Eastgaard, 32, who was the passenger in the SUV, has been charged with nine firearms-related offences.

He was under two firearm prohibitions that are not due to expire until 2014 and 2015 respectively, said Eiriksson.

'We are working with special prosecutions as well in dealing with these two individuals to hopefully ensure that they're behind bars.'—Staff Sgt. Gord Eiriksson

In November, Eastgaard was injured in a gun battle between feuding gangs in Chinatown.

"Here are two gentlemen who have lengthy criminal histories, and we are working with special prosecutions as well in dealing with these two individuals to hopefully ensure that they're behind bars," said Eiriksson on Friday.

He said police will be aggressively opposing bail for all suspects arrested on gang-related matters, whether or not they have previous criminal histories.

In an unrelated case on Thursday, police announced they had charged four people after a five-week investigation into a cocaine trafficking and manufacturing operation.

A woman was released on $5,000 bail, while a man was freed on $1,000 bail. The two other men remained in custody.

Two of those arrested were described as " known gang associates," but police did not disclose if they were the ones released on bail.

Two rival groups — Fresh Off the Boat (FOB) and Fresh Off the Boat Killers (FOBK) — have taken their grudges to Calgary streets with deadly, daytime shootings.