A day after a Punjab government aircraft violated the no-fly zone over Prime Minister Atal Bihari Vajpayee's residence in New Delhi, civil aviation authorities were yet to take a decision over the fate of the two pilots.

Sources said the authorities were awaiting instructions from Civil Aviation Secretary K Roy Paul, who is out of station and is likely to reach New Delhi on Wednesday.

According to the sources, the interrogation of C P Singh and Surinder Kapoor was completed on Monday evening. The duo told the investigators that they could not land at Safdarjung Airport during their first attempt as "birds were flocking around the runway".

The pilots, one of whom is a retired Indian Air Force pilot, said they had to take a diversion due to the birds and drop the height of the ten-seater 'King Air' aircraft.

Director General of Civil Aviation officials had completed their investigations.

The pilots had been grounded, sources said, adding that the aircraft was in DGCA's custody.