Canada was warned before protests that violent extremists infiltrated convoy

But it concludes that the potential for violence remained very real.

As the occupation dragged into its second week, Itac issued another report on 8 February.

Earlier this week at a blockade at the Coutts border crossing in Alberta, police arrested four men and charged them with conspiring to kill police officers and civilians.

On Wednesday, the public safety minister, Marco Medicino confirmed that some of those arrested had ties to some extremist elements in Ottawa. Some of the men arrested are believed to belong to a loose-knit group known as Diagolon.

The purpose of Itac is to provide various levels of local law enforcement with reliable information on emerging threats, said Stephanie Carvin, a former intelligence analyst with the Canadian Security Intelligence Service who now teaches at the Norman Paterson School of International Affairs at Carleton University in Ottawa.

Carvin said intelligence agencies had been briefing the Canadian government as far back as late December on the possible threat posed by the convoy.