Canada will launch air strikes against the Isis (also known as Islamic State) militant group in Iraq following a request for assistance by the US.

A senior government official revealed the news to agency reporters on the condition of anonymity, telling them that Prime Minister Stephen Harper will announce details about the attacks later on 3 October.

By speaking publicly about the plans before the announcement, the official in question has contravened government protocol.

The deployment of fighters to the war-torn Middle East country has not yet been voted on in Canadian Parliament. However, Harper's Conservative government has the majority of seats so the plans are expected to pass.

Canada is among dozens of countries, including the UK, that have signed up to the US-led coalition fighting the IS jihadist group in Iraq and Syria.

Canada's former Liberal government refused a US request to send troops to Iraq when George W Bush led an American invasion in 2003, straining ties between the neighbouring countries.