Afghan airline Ariana has denied one of its planes crashed, prompting questions about the aircraft that came down in eastern Afghanistan on Monday.The plane came down in Deh Yak district in Ghazni province, south-west of the capital Kabul, in an area with strong Taliban presence.Local officials initially said it was a passenger plane belonging to Ariana.The airline issued a strong denial, saying it only had two planes in the air and that they were safe.Mirwais Mirzekwal, chief executive of Ariana, told BBC Persian that one flight was travelling from Herat to Kabul, and had landed and that the other was flying to Delhi and was on track to land soon.Afghanistan's aviation body also announced that no civilian planes had crashed, and Taliban spokesman Zabihullah Mujahid told the BBC that his group had not yet located the aircraft.Ghazni police commander Ahmed Khalid Wardak told the BBC that there was no information about casualties and that it was unclear what had caused the plane to crash. He added that the aircraft had been set on fire.Iranian state media also published footage it claimed was of the aircraft and speculated that it may have belonged to the US Air Force - although these claims have not been verified.