"Our search for the suspect is still ongoing," RCMP Cpl. Chantal Farrah told a news conference Thursday afternoon. "Our focus remains in the mountain north area."
Farrah urged residents to keep their doors locked. "Stay at home, bar your doors and be vigilant," she said. "I know it's hard for families. You are in your house, you are locked, you have your kids, you want to go outside. But the police are saying to stay in."
Police were using air support, tactical teams and canine units, she said. Several hundred officers from New Brunswick and elsewhere from across Canada were involved.
"We have deployed a large amount of resources from here and elsewhere, and we are well-equipped to face this situation," Farrah said.
The 24-year-old suspect, Justin Bourque, was spotted three times around the search area Thursday morning, said Commander Marlene Snowman.
Bourque was wearing military camouflage and carrying two rifles in a picture released by police on Twitter.
At one point, he was seen coming in and out of a wooded area, Snowman said. "He's capable of moving into the wooded area and out," she said.
Investigators have not determined a motive for the shooting Wednesday evening, in which three officers were killed while responding to a call about an armed man at the north end of Moncton. Two other officers were wounded.
Police declined to identify the dead or injured officers.
It was the deadliest attack on the Royal Canadian Mounted Police since four officers were killed by a gunman on a farm in the western Canadian province of Alberta in 2005. That attack remains the deadliest on Canadian police officers in 120 years.
Snowman said Bourque was not known to police.
Schools and government offices were closed, and the city pulled its buses off the roads. Mail delivery was suspended.
Police commandeered armored trucks and told residents to stay indoors.
Commanding Officer Roger Brown said the two wounded officers underwent surgery for non-life-threatening injuries Thursday and he met with their families. One was later released from hospital.
"The RCMP family is hurting. As is Moncton, New Brunwick and our country," Brown said.