New Delhi, Oct 3 (IANS): Indian securities authorities were on alert following a bomb threat on board an Iranian passenger flight when it was approaching Delhi.

Sources claimed that the Mahan Air flight, which was in Indian airspace when the airline received the bomb threat, was denied permission to land in India due to technical reasons.

As per a flight tracking website Flightradar, the plane was on its way from Tehran in Iran to Guangzhou in China.

"IAF fighter aircraft were scrambled, which followed the aircraft at a safe distance. The aircraft was offered the option to land at Jaipur and then, at Chandigarh. However, the pilot declared his unwillingness to divert to either of the two airports," said a source.

Sources claimed that after a while, intimation was received from Tehran to disregard the bomb scare, following which, the aircraft continued its journey towards its final destination.

All actions were taken by IAF as per the laid down procedure, jointly with Ministry of Civil Aviation (MoCA) and Bureau of Civil Aviation Security (BCAS). The aircraft was under close radar surveillance by the Air Force throughout the Indian airspace, said a source.

The Mahan Air flight was in Indian airspace when the airline received the bomb threat.

The flight continued its journey to China after clearance from the authorities as it was not allowed to land in Delhi and Jaipur.

As per the sources, a call regarding the bomb threat on the flight was received at around 9:20 a.m. on Monday.

Sources said that while the nature of the threat is still unclear, following the call, the authorities at Delhi airport were immediately put on alert and permission was sought for landing. However, permission was not granted due to technical reasons and the plane was diverted to Jaipur.

Sources said that the plane was not allowed to land in Jaipur and it finally headed towards its destination.