At least four people, including two police officers, have been killed in a shooting incident at an apartment complex in the eastern Canadian city of Fredericton, police said.
Police in Fredericton, a city of about 56,000 that is the capital of the province of New Brunswick, said there had been multiple fatalities.
External Link: @CityFedPolice:UDPATE: At this time we can confirm that we have one suspect in custody. Police continue to have the Brookside area contained for the foreseeable future as the investigation is ongoing. Please continue to avoid the area and follow us for the facts.
Another police tweet said one person had been taken into custody and was being treated for "serious injuries related to … shooting".
Police have since confirmed "there is no further threat to the public," and said lockdowns were no longer required.
"Police still have the crime scene contained, and will be working the investigation for some time," the Fredericton Police said in a tweet.
Justin Mclean, who lives in the complex, said he tried to help.
"I just woke up and heard gunshots and I looked outside my window. There was basically three dead people laying there. It wasn't a pretty sight," Mr Mclean told the Canadian Broadcasting Corporation.
"The cops were trying to put one of the officers into the vehicle so they could take him out to safety."
Canadian Prime Minister Justin Trudeau said it was "awful news coming out of Fredericton".
"My heart goes out to everyone affected by this morning's shooting. We're following the situation closely,"he said on Twitter
In 2014 in another mass shooting in Moncton, New Brunswick, three Royal Canadian Mounted Police officers were killed and two more were wounded.
At the time, the incident was one of the worst of its kind in Canada, where gun laws are stricter than they are in the United States and deadly attacks on police are rare.
But a proliferation of weapons has led to an increase in gun crimes in recent years.
On Thursday, Ontario pledged more money for police and to keep suspects behind bars while they await trial on gun crimes charges, as the Canadian province grapples with rising shootings involving domestically obtained weapons.