The US government has extended its condolences to the relatives of those killed in an air crash near the central Iranian city of Qazvin.

All 168 people aboard the Tupolev plane were killed in the crash on Wednesday.

Washington "extends it condolences to the families of those who lost their lives in today's crash," read a brief statement by the US State Department Spokesman Ian Kelly.

"We are working through the US Embassy in Yerevan and the Swiss Protecting Power in Iran to determine whether any American citizens were on board," the statement said.

MGH/SME/RE