Montreal police have quietly stepped up security measures following the killings of two Canadian soldiers last week.

The front doors of the police headquarters are now locked and armed police officers are on duty inside.

The police brotherhood said the department is not doing enough to protect officers, responding to a report of new threats against officers in Montreal and Quebec City.

Commander Ian Lafreniere said he has received no alerts of new threats and that extra security measures have been in place since ISIS threatened figures of authority in several countries, including Canada, last month.

“The best strategy is the one that nobody knows about it but yes we enforce security in front of buildings and yes we (have) more police officers,” he said.

Montreal police are working with the RCMP and the Surete du Quebec on a special task force against terrorism.