Canada has raised its terror threat level from low to medium but has stressed there is no specific threat.
A government official said the move was in response to an increase in online “general chatter” from radical groups including Islamic State and al-Qaeda.
On Tuesday a Muslim convert was killed by Quebec police after deliberately hitting two soldiers in his car, killing one and injuring another.
A minister said it was a “terrible act of violence against our country”.
Public Safety Minister Steven Blaney said the attack was “clearly linked to terrorist ideology.”
Ministry spokesman Jean-Christophe de Le Rue said on Tuesday that the increased level “means that intelligence has indicated that an individual or group within Canada or abroad has the intent and capability to commit an act of terrorism”.
The dead soldier was identified on Tuesday as Warrant Ofc Patrice Vincent, a 28-year veteran of the Canadian armed services. He was struck by Martin Couture-Rouleau, 25, one of 90 suspected militants who are being tracked by the Canadian authorities.
After striking the officers, Couture-Rouleau fled and was chased by police at high speed for about 4km (2.5 miles), until the car drove off the road and rolled over several times.
He then left the car brandishing a knife, and police opened fire. Couture-Rouleau was taken to hospital where he died some hours later.
Royal Canadian Mounted Police (RCMP) Commissioner Bob Paulson said that the authorities had been tracking the 90 suspected militants – including Couture-Rouleau – because they may have intended to go abroad to join militant groups.
RCMP Supt Martine Fontaine said authorities seized Couture-Rouleau’s passport in July when he tried to travel to Turkey. He was arrested but police lacked evidence to charge him with a crime.
Supt Fontaine said authorities had met him several times, most recently on 9 October, and had met his parents and the imam at his mosque in an effort to get him to change his views.
The attack took place following a vote in parliament this month that authorised Canadian warplanes to bomb Islamic State militants in Iraq.
Defence Minister Rob Nicholson said the soldier’s death was “a senseless act” which only strengthened Canadian resolve to take on militant groups such as IS.
The US has also condemned the attack.