A special Indian Air Force aircraft, which was to carry President A P J Abdul Kalam to Delhi from Chennai, was delayed late on Monday night following an anonymous telephone caller's claim that a bomb has been planted in the plane, airport sources in Chennai said.     

The sources said the caller rang up the St Thomas Mount police control room saying that a bomb has been planted in the plane of the Tamil Nadu governor.

But since there was no special plane for the governor and the President's special aircraft was scheduled to leave Chennai, the authorities took no chances and checked all the baggage and other material that were on the IAF plane after unloading them.

The thorough search of the plane was on well past midnight.

The caller spoke in Tamil and efforts were on to trace the person, said the sources.

Kalam, who was to reach Delhi at 0100 hours of September 5, is now expected to land in the national capital hours behind schedule.