Bishkek, Kyrgyzstan/Moscow - Kyrgyz authorities Monday ruled out terrorism as the cause of an air crash in which at least 65 passengers died near the Central Asian state's capital of Bishkek, saying mechanical failure was the probable cause.

Reports on the number killed and injured when the Itek Air Boeing 737 came down on Sunday evening varied.

The Interfax news agency reported that the Kyrgyz government had ruled out terrorism, saying the crash was likely caused by engine failure or an error in the control system.

Moscow sent a team of investigators to help determine the cause.

The airliner, which was bound for Tehran from Bishkek, was completely gutted by fire, according to the Civil Defence Ministry.

Only 22 of the 90 people on board survived, the Kyrgyz government said, according to Interfax. Three children, aged between 12 and 15, were among the survivors.

Forty-four of the passengers killed and 10 of those injured were Iranian, the network Khabar reported in Tehran Monday.

The news agency Mehr said that the Kyrgyz youth basketball team on board was on its way to Tehran to attend Thursday's Asian basketball championships.

Other passengers were from Kyrgyzstan, Kazakhstan, Canada, Turkey and China.

Iran's Foreign Ministry was to announce details later Monday of the Iranians aboard.

Rescue workers and police cordoned off the crash site, where Kyrgyz Prime Minister Igor Chudinov visited Sunday evening.

Itek Air is one of more than a dozen Kyrgyz airlines that are banned from flying to the European Union as a result of safety concerns.

Transport Minister Nurlan Sulaimanov said the plane had been manufactured in 1979 and had been inspected only two months previously.

Citing the Iranian Civil Aviation Organization, Iranian official news agency IRNA confirmed that the plane was from the Kyrgyz national fleet and not Iranian-owned.