A Canadian submarine had some trouble on the weekend but remains at sea.

An electrical glitch caused a transformer to melt and generated smoke in the engine room of HMCS Windsor.

The navy said the crew was ordered to emergency stations on Sunday morning.

However, there were no injuries and the navy says the Victoria-class sub remained at sea and fully operational.

The incident occurred while the submarine was submerged.

The problem was isolated to the transformer, which was replaced, the navy said.

The navy is investigating the cause of the problem.

The sub was one of four used diesel-electric vessels the Canadian government obtained from Britain in an $891 million lease-to-purchase deal.

The other three subs are HMCS Chicoutimi, Victoria and Corner Brook.

In October 2004, an officer on Chicoutimi died of smoke inhalation after an electrical fire broke out off the coast of Ireland. The sub was travelling to Canada from Scotland.

In the wake of the Chicoutimi tragedy, the two functioning subs were pulled from service for electrical upgrades -- something a navy report later said was unnecessary.

When the Victoria went back to sea in May, it returned to port after a day when some unusual sparking in the motors was recognized.

"This is a shakedown period. We anticipate that there will be things like this that occur and the submarine will be coming and going as we work through those problems," Capt. Chris Henderson of the Dept. of National Defence said at the time.