Prime Minister Manmohan Singh's [Images] aircraft got disconnected with the control tower of the Delhi airport for nine seconds recently, Minister of State for Civil Aviation Praful Patel informed the Rajya Sabha on Tuesday.

In a written reply, he said communication remained intermittent for a period of four minutes and 40 seconds.

Patel said the incident occurred due to the intermittent contact in the mike provided at the control tower, which caused momentary failure of communication between the control tower and the prime minister's aircraft.

However, he said that as per the findings of preliminary inquiry conducted in the matter, immediate action was taken to suspend two executives on duty at that time.

To avoid recurrence of such incidents, Patel said instructions have been reiterated to all concerned with respect to handling of VVIP aircraft and additional guidelines circulated for strict compliance.

Supervision of VVIP movement and coordination of VIP aircraft is performed by senior officers on duty present at that time in the control tower, he said adding, besides mandatory checks have also been introduced for services in facilities.