A Punjab government plane on Monday evening created a security scare when it flew low over the 7, Race Course Road residence of Prime Minister Atal Bihari Vajpayee.

Prime minister's security went into a high-alert mode as soon as the aircraft was spotted on a radar. The plane was later forced to land at the Safdurjung Airport, official sources said.

The plane's pilot has been identified as Captain C P Singh. He is being  questioned by the Directorate General of Civil Aviation officials and the Special Protection Group, which is in charge of the prime minister's security.

The plane, which took off from Patiala, was scheduled to fly Punjab Chief Minister Captain Amarinder Singh to Punjab, the sources said.

Officials of the Bureau of Civil Aviation Security have also rushed to the Safdurjung airport.

The air space over Delhi's VVIP areas, including those housing the offices and residential premises of the President, the prime minister and the deputy prime minister was made a no-fly zone following September 11, 2001 attacks in the United States.