New Delhi, Aug 15 (IANS): Independence Day celebrations at the Red Fort passed off without any untoward incident on Thursday, with several layers of security in place.

The national capital was enveloped in a thick security blanket with the deployment of police and paramilitary forces, with the maximum attention paid to the 17th century Red Fort where Prime Minister Narendra Modi addressed the nation.

The National Security Guards (NSG), soldiers as well as SPG and SWAT commandos were engaged in ground and air surveillance.

Cameras with facial recognition software were used for the first time. Anti-drone detection system was deployed to secure the skies while special control rooms monitored alerts and coordinated with security agencies.

Delhi Police spokesman Mandeep Singh Randhawa said that 20,000 personnel were deployed at the Red Fort and on the roads leading to it.

From 4 a.m. to 10 a.m., only vehicles with special labels were permitted to go towards the Red Fort.

Sniffer dogs were deployed to check vehicles in parts of Delhi.

Delhi Metro services ran normally, with restrictions on entry and exit only at some stations on the Violet Line that passes through Old Delhi where the Red Fort is located.

The Metro stations affected were Lal Quila, Jama Masjid, Delhi Gate and ITO.