The Calgary police guns and gangs unit has arrested seven suspects in connection with a serious assault and a subsequent shooting last month.

The assault happened on Feb. 20 outside a business in the 4800 block of Macleod Trail S.W.

A few hours later police were called to a residence in Martindale in northeast Calgary for reports of shots being fired.

Nobody was hurt in the shooting, which left four bullet holes in a house.

Police believe it was in retaliation for the assault.

On Tuesday, officers carried out search warrants at a house in the hamlet of Delacour, just northeast of Calgary.

Officers seized almost 15 grams of heroin, a pump-action shotgun and two rifles, among other things.

The seven suspects face 31 charges including drugs and weapons offences, as well as careless storage of firearms and breach of recognizance.

The guns and gangs unit is still investigating the circumstances surrounding the assault and the shooting, and more charges are expected.