TORONTO -- A Canadian NATO helicopter has been involved in an incident off the coast of Greece and a search and rescue mission is currently underway.

In a pair of tweets, Canadian Armed Forces Operations said it lost contact with the CH-148 Cyclone, which had been deployed onboard the Halifax-class frigate HMCS Fredericton, and “was participating in Allied exercises off the coast of Greece” as part of Operation Reassurance.

The military said it could not provide further information at this time because the situation was evolving, but the Armed Forces later confirmed in another pair of tweets that they have contacted all primary family members of those who were on board the helicopter, and that "search efforts continue with our Allies."

The CAF confirms we have contacted all primary family members of those who were on board the CH-148 Cyclone helicopter that was involved in an accident in the Mediterranean Sea. pic.twitter.com/5wVjRjboCl — Canadian Armed Forces Operations (@CFOperations) April 30, 2020

In a tweet, Prime Minister Justin Trudeau said the helicopter had “gone missing” and that he’s been spoken to Defence Minister Harjit Sajjan regarding the situation.

“Updates will be provided as soon as possible,” he added.

A Canadian helicopter involved in Op REASSURANCE with NATO allies has gone missing off the coast of Greece. I have spoken with Minister @HarjitSajjan, and search and rescue efforts are currently underway. Updates will be provided as soon as possible. — Justin Trudeau (@JustinTrudeau) April 30, 2020

Conservative Leader Andrew Scheer called news of the helicopter’s disappearance “very troubling.”

“As we await more details from the Department of National Defence and Canadian Armed Forces officials, our thoughts and prayers are with the crew’s family and the members onboard,” he wrote in a tweet.

Very troubling. As we await more details from the Department of National Defence and Canadian Armed Forces officials, our thoughts and prayers are with the crew’s family and the members onboard @HMCSFredericton. https://t.co/IPUTrBOKuo — Andrew Scheer (@AndrewScheer) April 30, 2020

In a statement, Col. Juanita Chang, chief of Public Affairs for the Supreme Headquarters Allied Powers Europe, confirmed also the incident, but offered few additional details.

“I confirm there has been an incident involving a helicopter from a ship under NATO command,” Chang said in the statement. “There is currently a search and rescue operation being conducted and national notifications taking place. “

In January, HMCS Fredericton left Halifax for a six-month deployment around Europe for Operation Reassurance, which aims to “reinforce NATO’s collective defence” and show solidarity with allied countries in Central and Eastern Europe, according to the Canadian Armed Forces website.

Several Canadian warships involved in the mission had been recalled due to COVID-19, but HMCS Fredericton remained.

The vessel visited Italy in March and was scheduled to visit Greece and the Black Sea as one of eight warships in NATO's Standing Maritime Group 2, which provides a military presence in the Mediterranean Sea.

The Canadian military began using the Cyclone helicopters for training purposes in 2015, after more than a decade of expensive delays with the manufacturer Sikorsky. It wasn’t until 2018 that the military began using them in real missions.

The military was supposed to have received 28 Cyclones from Sikorsky in November 2008, but to date has only received 18.

With files from The Canadian Press