LONDON (AP) — British military authorities are trying to find out who hacked the army’s social media accounts over the weekend, flooding them with cryptocurrency videos and posts related to collectible electronic art.

The investigation was launched after authorized content on the army’s YouTube account was replaced with a video feed promoting cryptocurrencies that included images of billionaire Elon Musk. The Army’s Twitter account retweeted a number of posts about non-fungible tokens, unique digital images that can be bought and sold but have no physical counterpart.

“Apologies for the temporary interruption to our feed,’’ the army said in a tweet posted after the Twitter account was restored on Sunday. “We will conduct a full investigation and learn from this incident. Thanks for following us, and normal service will now resume.”

The Ministry of Defense said late Sunday that both breaches had been “resolved.”

While internet users were unable to access the Army’s YouTube site on Monday, a spokesperson said the site was down for standard maintenance. The Twitter feed was operating normally.

Although U.K. officials have previously raised concerns about state-sponsored Russian hacking, the military did not speculate on who was responsible for Sunday’s breaches.

“The army takes information security extremely seriously, and until their investigation is complete it would be inappropriate to comment further,” the Ministry of Defense said.