WINNIPEG -- A weekend of what police called stunning violence has become even more violent after four people -- including an infant -- were victims of a shotgun attack.

Winnipeg police said around 3:15 p.m. a suspect knocked on the door of a house in the 400 block of Flora Avenue. The suspect, believed to be a man, began shooting after entering the house, police said. The suspect then left the area.

Four people were taken to hospital, two in critical condition and two in stable condition. Police said the three adults are now in stable condition, adding the infant's injuries are not believed to be life-threatening.

“If everybody can come away in this with non-life-threatening injuries, it’s almost a miracle,” said Const. Rob Carver with the Winnipeg Police Service. “I would say it’s all hands on deck at this point.”

After three people were killed this weekend, Carver said this was one of their busiest days he has seen in a long time. Winnipeg police said the tragic incidents all occured within 18 hours of each other and have put a significant strain on police resources.

"We will continue to triage all calls for service and prioritize personal and public safety over property concerns and incidents where there is no immediate threat," police said in a news release Sunday evening. "We ask those waiting for a police response during this time to please be patient."

Police were still on scene at Flora Avenue on Sunday afternoon, with at least two cruisers in the area and the street taped off.

Police did not say if they have made any arrests.

The major crimes unit is investigating. Police are asking anyone with information that may help investigators to call -204-986-6219 or Crime Stoppers at 204-786-8477.