Police in Sweden are investigating reports that two Swedish citizens were killed by Isis in Iraq.

The Ministry of Foreign Affairs (UD) has so far not confirmed the information about the deaths published by tabloid Expressen at the weekend. The Swedish embassy in Iraq is in contact with local authorities.

“Given the circumstances it’s not certain we will be able to confirm the deaths – not at present in any case. That’s why we’ve referred the matter to the police,” UD press spokesperson Lina Eidmark told news agency TT.

“I can’t say more about their identity or background, just that they were living in Sweden,” Kristian Ljungberg from Sweden’s police said.

Questions were first raised when videos of an apparent execution were published, then subsequently translated to Swedish by Expressen. In the video two men are accused of belonging to a Shiite militia before being shot.

According to relatives who contacted Expressen since the video was released, the two men are aged 50 and 20, lived in western Sweden and have been missing since the end of last year.

Expressen says the men travelled to Kirkuk in northern Iraq to meet relatives before going off the radar.