North American ISIS spokesperson in Syria
North American ISIS spokesperson in SyriaScreenshot

Intelligence officials told NBC News that Canadian authorities have heard would-be terrorists discussing potential ISIS-inspired "knife and gun" attacks against U.S. and Canadian targets inside Canada.

While the intelligence officials said that some of the discussions raise the possibility of attacks on U.S. citizens and other U.S. and Western targets in Canada, they have not picked up talk of anyone crossing the border into the U.S. to stage attacks.

They stressed that the possible attacks were at the "aspirational," rather than implementational stage.

Intelligence officials say that Canadian authorities are monitoring "hundreds of people" in Canada who have either gone to Syria to link up with ISIS and other Islamist groups and returned, or who have tried and failed to make the trip. “The unknowns, those inspired by ISIS but as yet on no radar, add to the worry, helping to make this what U.S. and Canadian officials have said is the most dangerous time since 9/11 for a domestic terror attack,” said NBC.

According to Canada's National Post, Canada’s top security officials said Wednesday that the RCMP (Royal Canadian Mounted Police) are investigating 63 national security cases linked to terrorism and involving 90 suspects.

Wednesday night, Jean-Christophe de la Rue, a spokesman for Public Safety Minister Steven Blaney, said in an email regarding the NBC report: “While I cannot comment on operational matters of national security, I can say that security agencies are constantly evaluating the terrorist threat and taking action to protect Canadians.”

Speaking earlier to a Commons committee, Blaney said Canada’s security strategy is “working but the threat is there, and that’s why we need to keep on adjusting to the threat.

The committee meeting focused on Canadian citizens joining terror groups abroad. It, and the NBC report, came one day after Parliament voted to join U.S.-led airstrikes in Iraq against the Islamic State (aka ISIS).

The head of Canada’s spy agency said there hasn’t been a substantial increase in the number of Canadians going abroad for terrorist purposes since he spoke to a Senate committee on the subject in February.

“The threat is real [but] we don’t want to sound alarmist,” said Canadian Security Intelligence Service (CSIS) Director Michel Coulombe. “We know where they are.”

He confirmed that the CSIS knows of 130 to 145 Canadians involved with terror groups in Arab countries — 30 in Syria — and that 80 Canadians are estimated to have returned home after fighting with terror groups.

Coulombe said the activities of those 80 Canadians range from fundraising and propaganda work to violent acts.