Fears of attacks by militants on the Indian capital have prompted authorities to increase security in the city, a top police official said today.
"After what has happened in the United States, there has been a quantum jump in the threat perception," Mr Radhe Shyam Gupta, special commissioner for security and operations with Delhi Police, told reporters.
"We are on high alert," he said but did not give details.
The number of police patrols in New Delhi, especially in the city's diplomatic district where the US embassy is located, have increased since the devastating aerial attacks on the World Trade Center and the Pentagon.
The air force has stepped security in the airspace over the capital.
"All precautionary measures which are appropriate to the new situation have been taken, including tracking of all aircraft near vulnerable areas even more carefully," a defence official said.
Authorities are taking no chances because the city has been a target of militant attacks in recent years. Last year, a historic fort was attacked by a suicide squad of a Kashmiri militant group, killing three people.
One magazine quoted intelligence officials as saying the presidential palace, the prime minister's residence as well as the home (interior) and foreign ministries were likely targets after the attacks in the Unites States.