“No names are being released at this time. Please appreciate this is a difficult time for their families and our colleagues,” Fredericton police said on Twitter.
A suspect is in custody, and the crime scene has been “contained,” police said. They said the investigation is ongoing and the suspect is being treated for serious injuries.
Police later said there was “no further threat to the public” and no need for any lockdowns.
“Our thoughts and prayers are now with the families, friends and colleagues of the two brave Police officers who gave their lives in order to protect and serve and with the families of the other two victims of this senseless act of violence,” said a tweet from the city of Fredericton on behalf of Mayor Mike O’Brien, the City Council and other municipal employees.
“The next few days will be a challenging time for our community as we deal with a loss that will no doubt be felt by many.”
A spokeswoman for Dr. Everett Chalmers Regional Hospital said it was treating multiple victims from the shooting.
The shooting occurred around 7 a.m. (6 a.m. ET) in the Brookside Drive area of the city of about 60,000 people, police said.
“We extend our sincerest condolences to Chief Leanne Fitch, the officers of the Fredericton Police Force, and everyone affected by today’s events,” the city said in its tweet.
“Not enough can be said about the courageous efforts shown today and everyday by members of the Fredericton Police Force, the first responders involved, and all those who respond to the call for help.”
CNN network partner CTV said its reporter there said “police appeared to be focused on one particular residence” and that he heard four shots during a five-minute stretch.
“There is a police officer standing outside with a gun,” CTV Atlantic’s Nick Moore said on CTV’s “Your Morning.”
CTV said Moore reported that “police escorted people from their homes” after announcing a suspect was in custody.
New Brunswick Premier Brian Gallant said in a statement that “we are all shocked and saddened to learn this morning of the ongoing tragic incident.”
“I offer my condolences, thoughts and prayers to the victims and their families. During this difficult time, our thoughts are also with the courageous women and men on the front lines working to keep us safe,” he said.
“At this time, I would ask New Brunswickers, particularly those in areas identified by police, to keep informed about the situation as it develops and follow the instructions of law enforcement officials working in the area.”
Canadian Prime Minister Justin Trudeau offered his condolences to those affected by the shooting and praised the actions of first responders.
“This morning, first responders rushed to the scene of danger. They did not think twice about what they had to do to keep their fellow Canadians safe,” Trudeau’s statement said. “They were unflinching in their duty.”
“We will not forget the two fallen police officers whose sacrifice no doubt saved lives and prevent even greater tragedy,” it said, adding the Royal Canadian Mounted Police was ready to assist Fredericton police, which is leading the investigation.
Many facts surrounding the incident remain unknown, and the investigation is in its early stages, said Ralph Goodale, Canada’s minister of public safety and emergency preparedness.
“What we do know is that four Canadians are dead, and that is a huge tragedy for the whole country, and all Canadians I’m sure would want to extend their condolences and their sympathies to the families and to all those who suffered in this incredible loss, including two police officers,” he told reporters.
New Brunswick is one of Canada’s eastern Maritime provinces.
Growing gun violence in recent years has been an issue in Toronto, Canada’s most populous city.
A shooting rampage last month in that city left two people dead.
Asked whether Friday’s incident signaled a need for new initiatives to combat gun violence, Goodale said he couldn’t comment directly on the day’s events but that the Canadian government took the issue “very seriously.”
He pointed to legislation meant to increase background checks, improve the license verification process and keep updated records, and to investments in programs meant help the federal government work with provincial governments to deal with guns and drugs.
“Canada is a safe and secure country,” Goodale said. “In fact, most crime rates are going down and have been going down for several decades, but the incidents of violence with firearms have been going up over the course of the last five years, and our initiatives are aimed specifically at that objective.”
CNN’s Paula Newton contributed to this report.