STOCKHOLM, Jan. 8 (Xinhua) -- Ten Swedish citizens are among the more than 170 people died onboard the Ukrainian plane that crashed in Iran on Wednesday, according to the Ukrainian foreign ministry.

"Ukraine has reported about ten people, but there may be more," Swedish Foreign Minister Ann Linde told the country's TT news agency, adding that together with the Swedish Embassy in Tehran, efforts are being made to confirm the number of Swedes killed in the crash.

Linde wrote on Twitter that she "received with great sadness" the news of the plane crash.

"Swedes were on board... My deepest condolences to the relatives. It is a tragedy for those affected, their families and friends. The Foreign Ministry's crisis organization has started," she wrote.

"We are working intensively to confirm" the number of Swedish victims, Diana Qudhaib, press officer at the Swedish Ministry of Foreign Affairs, told Swedish Television (SVT) News.

"It is important to inform relatives first before we publicly confirm deaths," she said.

The Swedish ministry also announced that their continuous work assumes "that there will be a number of deceased Swedes, unfortunately."

In addition to Swedish citizens, most victims of the plane crash are Iranian, Canadian citizens, according to the Ukrainian foreign minister.