Security personnel are on high alert at embassies and other installations of the United States, Britain and other countries in New Delhi on the third anniversary of terrorist attacks in Washington and New York.

Apprehensive that terrorists might attempt to carry out strikes to mark the events of September 11, Delhi Police said that it has mounted vigil in the Diplomatic Enclave in the Chanakyapuri area. 

Security personnel have been particularly told to be on high alert in the vicinity of the US Embassy, the Ambassador's residence, the American Center, the British High Commission, British Council and installations of Australia, as these are feared to be the main targets of terrorists. Patrolling around these installations has been stepped up to ensure no unscrupulous elements gain access to these venues, which are under a thick security cover since the terrorist attacks in the US three years ago. 

"The security personnel deployed at these places have been sensitised and asked to remain vigilant today as there is apprehension that terrorists may try to cause harm to these installations," the sources said, even as they insisted that have been no specific warnings or intelligence inputs.