New Delhi/Uttar Pradesh, Dec 6: National capital New Delhi and Uttar Pradesh were on high alert on Thursday on the 15th anniversary of the demolition of Babri Masjid in Ayodhya.

The demolition of the 16th century mosque on December 6, 1992, triggered off nationwide communal riots that took a heavy toll of human life.

According to the Delhi police, six people suspected Harkat-ul-Jehadi Islamia (HuJI) militants have sneaked into the capital from Deoband in Uttar Pradesh to carry out attacks.

As per the Intelligence Bureau, they entered the Seelampur area of East Delhi on Wednesday. One of them is believed to be of African origin, while the other two are Afghan nationals.

Barricades have been placed at all crossways to keep vigil on untoward activity.

In Uttar Pradesh, security has been beefed up. Heavy security was deployed at the acquired land complex in Ayodhya, the Kashi Vishwanath temple-Gyanvapi mosque and Lord Krishna Temples of Mathura.

Police and paramilitary personnel are also guarding the Taj Mahal in Agra.

"Our force is deployed in and around the monument. Visitors are being checked with a metal detector. We are also conducting surprise checks during day and night," said R.K. Singh, a Deputy Commandant of the Central Industrial Security Force (CISF).

In Ayodhya, police have been frisking people visiting religious complexes in the area.

In Dehradun, security forces launched a drill ahead of Prime Minister Manmohan Singh's visit to the Indian Military Academy (IMA).

"Considering the recent events, we have decided to beef up security in the area. Whatever we deem is necessary, we are doing it," said Subhash Joshi, Director General of Police (DGP), Uttarakhand.

Tight security arrangements have also been made at all major railway stations in Chennai. (ANI)