OTTAWA — It seems the Maltese revel in their peace and quiet -- even when it's at sea.

A Canadian warship on its way to the eastern Mediterranean caused a bit of ruckus off the island nation.

Earlier this week, the Halifax-based frigate HMCS Charlottetown conducted a small-arms firing exercise on the deck of the ship, which is routine training for the counter-terrorism mission the ship is about to begin.

Sailors were firing 9 mm pistols towards the empty ocean when they were ordered to stop.

Lt. Mark Fifield, a spokesman for the Royal Canadian Navy in Ottawa, says Maltese Coast Guard officials hadn't authorized the exercise and shut it down after being notified over the radio.

Under international convention, warships conducting any firing drills in the waters of other countries are required to warn other vessels in the area and the host nation.

Fifield said the skipper of the Charlottetown didn't realize his warship had crossed into Maltese waters, but added that the radio warning had still been broadcast.

"No other vessels were in proximity to Charlottetown at the time of the incident and there was no risk to public safety," he said.

Canada delivered a note of apology to Malta over the incident and Fifield said it was something the navy "deeply regretted."

He said the weapons drill, conducted to ensure sailors are ready for the boarding of suspicious vessels, later resumed but only after the warship had hit international waters.

The frigate is on its way to join the NATO standing fleet, which is conducting counter-terrorism patrols. It was ordered to take up the post by the Conservative government, which wants to maintain a presence in the region given the instability and uprisings in Arab countries.