Ottawa police are investigating whether three men charged with a series of armed robberies in Ontario and Quebec are also responsible for an armed robbery at a Stittsville bank earlier this month.

Three Quebec men were arrested and charged over the weekend with armed robbery after a Ontario Provincial Police-led investigation involving the Surete du Quebec, Ottawa police, Sault St. Marie police and Sudbury police.

The accused have been charged with stealing nearly $600,000 in seven robberies between March and September of this year.

Ottawa police said the accused are also believed to be involved in the robbery of a TD Bank in Stittsville on Sept. 12, but police have yet to charge them.

In that robbery, the suspects used a sledgehammer to break the glass and forced tellers at gunpoint to open the vault.

A similar tactic was used in a series of robberies in Waterloo, Sudbury and Sault Ste. Marie, Ont., and in Laval, Que., and Vaudreuil, Que.