New Brunswick RCMP have confirmed that three officers were shot and killed and two other officers were wounded by a heavily armed gunman Wednesday evening in Moncton.

A police manhunt is still underway for Justin Bourque, 24. The RCMP say Bourque is considered "armed and dangerous."

Paul Greene, an RCMP spokesman, said Bourque was last seen in the wooded area near the Pinehurst subdivision. Police are asking people to keep their doors locked and leave their outdoor lights on.

RCMP Const. Damien Theriault could not say how many police officers were involved in the manhunt.

Theriault, visibly emotional during a news conference, asked the public not to disclose any information about the police operation or locations of officers on social media.

Police officers take cover behind their vehicles in Moncton, N.B., following the shootings. (Ron Ward/Moncton Times & Transcript via The Canadian Press)

One witness near the scene of the shooting told CBC News he saw one officer bleeding from a wound toward the top of her head.

The witness said the RCMP rushed her away in a police cruiser. Hospital staff confirmed some of the victims arrived at the hospital in police cars.

Dr. Dhany Charest, the chief of staff at the Moncton Hospital, said two gunshot victims related to the tragedy were being treated. A third patient was being treated from a separate gunshot incident that occurred on Wednesday evening.

The hospital remains on lockdown with police and security guarding the building. The hospital had declared a "code orange" requiring all available staff to come to the hospital, but that was lifted around 1:30 a.m. AT.

Oh my God, there he is with camouflage and the headband and a gun, and it looked like a bow he had with him. And I mean he was just through our backyard. - Joan MacAlpine-Stiles, Moncton resident and witness

Hospital staff said the two people injured in the shooting are in stable condition. They could not confirm these people were RCMP officers, nor the gender of the injured.

Officials said operating rooms are being kept clear in case there are more casualties.

A police helicopter is flying in the area.

The RCMP said the police received a call at 7:20 p.m. AT about a man wearing camouflage and carrying guns.

Greene said additional police resources from across New Brunswick and Prince Edward Island are in Moncton to assist the RCMP in the manhunt.

'We're scared, obviously'

The shooting has rattled people living in the city's north end.

Joan MacAlpine-Stiles said she saw the shooter when she went to open up a window.

"It was really warm in the house, so we opened up the windows in the family room and there he was going across through the back with this rifle on his shoulder," she said.

An RCMP cruiser's window was shattered at the scene of the multiple shooting in Moncton, N.B. (Courtesy of Daniel St. Louis)

"I said, 'Oh my God, there he is with camouflage and the headband and a gun, and it looked like a bow he had with him. And I mean he was just through our backyard.'"

Vanessa Bernatchez posted a video on Facebook from the moment the gunman opened fire, apparently killing at least one RCMP officer.

Watching from inside her living room with several others, Bernatchez said it appears the Mountie didn’t see the shooter until the gunfire erupted.

“It was too late, he went down. We knew it was over,” Bernatchez told CBC News Network.

On the video, a man describes what’s happening outside.

“He shot him … he shot a cop,” he said.

“Oh my God,” Bernatchez screams. “Call 911.”

The video ends with her racing to the phone. Police and a tactical team arrived on the scene soon after, she said.

Will Njoku said he was emptying his dishwasher and putting his young children to bed just before 8 p.m. when he heard popping sounds.

"Within 30 seconds I heard sirens," he said.

Employees of a grocery store in Moncton, N.B., lock down their store during the police manhunt for the gunman. (Marc Grandmaison/Canadian Press) Njoku said he heard five more shots after the sirens.

"We’re scared, obviously. We’re more terrified for the people who this shooter is basically in their backyard. I can picture these people’s houses," he said.

When the news broke that there was a shooter on the loose, Njoku said, he went out on his street to warn his neighbours.

"I felt pretty dumb. But there was people going down there. I just know my neighbourhood. It’s just kid city," he said.

Premier 'shocked and saddened'

New Brunswick Premier David Alward issued a statement about the Moncton police shootings.

"I was shocked and saddened to learn of tonight's tragic situation in Moncton," Alward said.

Shattered glass surrounds a police SUV with multiple bullet holes in the front windshield at the scene of the shootings in Moncton, N.B. (Daniel St. Louis/Submitted) "On behalf of all New Brunswickers, I would like to extend my thoughts and prayers to those affected. I would ask NewBrunswickers, particularly in those areas identified by police, to follow the situation as it develops and to listen to the advice of police."

Moncton Mayor George LeBlanc also asked city residents to stay indoors.

"Terrible sad news for Moncton. Stay indoors and allow police to do their job. Prayers for the families," LeBlanc tweeted.

LeBlanc said at a news conference that he has confidence that police will apprehend the suspect and he said there is no need at this point to declare a state of emergency.

Prime Minister Stephen Harper commented on the shootings Thursday morning.

"On behalf of all Canadians, Laureen and I offer our deepest condolences to the families, colleagues and friends of those affected by this tragedy. We also offer our prayers for the speedy recovery of those injured," Harper said in a statement.

Harper is currently in Belgium to attend a G7 Summit meeting.

"This violent incident is a stark reminder that our men and women in law enforcement put their lives on the line in Canada every day to protect our citizens and communities," he said.

The CBC's Kate Letterick is on the scene. Follow @letterickCBC for emerging details.