A high alert has been sounded in the city following an email warning a repeat of Delhi high court blast that took place on September 7.
Elaborate security arrangements have also been made in Delhi and the National Capital Region for September 13, the third anniversary of the 2008 serial blasts that killed 25 people and injured a 100 in Delhi.
In an email sent to television channels on September 8, Indian Mujahideen, that was held responsible for the 2008 blast, claimed responsibility for the blast on September 7 and warned of a similar attack on "a shopping complex" on Tuesday.
Police said extra security personnel have been deployed at sensitive places including, malls, shopping areas, Metro stations, railway stations, airport and crowded markets.
Sources said over 20,000 personnel have been deployed across Delhi to prevent any untoward incident on Tuesday. Authorities in Noida and Gurgaon that have large concentration of malls have also increased police deployment.
"We are already on high alert after Wednesday's blast outside the high court. As part of security drill, we have intensified patrolling and checking across the city, including shopping malls, markets and other crowded places. Shopping mall operators have been asked to step up their security system. Local police officers are having regular meeting with them," said a Delhi police officer.
Gurgaon police conducted a security audit in malls last week and found some gaps. "We have asked mall authorities to fix these problems. Policemen in plain clothes have been deployed in all such areas," said Alok Mittal, joint commissioner of Gurgaon police.
In Delhi, informers have been deployed to keep a check on any movement of anti-national elements.
Specialised units like Quick Reaction Teams, SWAT and Vajra are being deployed. Police have also enhanced checking at Karol Bagh, Connaught Place and Greater Kailash.