Concord police said they seized a cache of drugs during a search of a Joffre Street address following a tip from the Royal Canadian Mounted Police about illegal drugs being shipped through the mail.

Officers seized a quantity of drugs believed to be fentanyl, methamphetamine, and MDMA. They also found a firearm, bullet-proof vest and ammunition.

The search was part of “Operation Granite Shield” and included members of the Concord Police Department, the New Hampshire State Police, Homeland Security Investigations, and the US Postal Inspection Service.

As part of the operation, police arrested Colin Dowling, 37, of Concord on an unrelated warrant.

This investigation remains open and ongoing, police said.