The photo of a medical vehicle with Russian plates somewhere on Stockholm’s Södermalm island emerged on social media Tuesday. Tweeters immediately wondered what exactly the ambulance, and people dressed in red medical uniforms with Russian imprints, were doing in the Swedish capital.

Against the backdrop of Sweden’s futile search for a ‘Russian submarine’ off the Stockholm coast in 2014, images of a real Russian vehicle in the heart of Sweden looked especially odd. Sweden’s Aftonbladet newspaper jumped on the story, saying the mystery of the Russian ambulance remains unsolved, further fueling the Swedes’ speculations.

Some joked that the ambulance was a “submarine on the land,” in an apparent reference to the notorious ‘Russian sub’ which triggered a massive and costly search involving the country’s military. The hunt for a foreign submarine, presumed to be Russian by the Swedish media, was launched off Stockholm in October 2014. For the record, the ‘enemy sub’ was never found.

READ MORE: Mysterious ‘Russian sub’ off Sweden may be Dutch – Defense Ministry source

More pragmatic and less suspicious people suggested the ambulance was attached to the Russian Embassy in Stockholm and was nothing to get excited about. They were closer to the truth.

As it turned out, the ambulance was not there to spy on Swedes. And it definitely wasn’t a transformer-submarine sought by the Swedish Navy. The reasons for its presence in Stockholm were quite plausible – the ambulance was from Russia’s private medical service in St. Petersburg and was despatched to help a Russian citizen who was injured while on a business trip to Sweden.

The ambulance took the Russian national from a hospital in the Swedish city of Orebro, and was returning to Russia via the Swedish capital when the medics noticed a sick passer-by in the street. Their Hippocratic Oath meant they could not ignore the incident, the medical service later confirmed in a statement.

The Russian medics administered first aid to the man before their Swedish colleagues arrived. They then continued on their way. People on social media, both Swedes and Russians, hailed the medics’ efforts, saying they are true Hippocrates’ followers who are ready to save people regardless of their nationality and circumstances.

“An ambulance is an ambulance everywhere,” the medical emergency team’s doctor Sultan Sharapudinov told Ruptly, confirming that the Swedish man they treated suffered an epileptic fit. “We have to provide help to any person. And it doesn’t matter if he is a foreigner or a Russian citizen.”