In the backdrop of Varanasi bomb blasts, the US Embassy in New Delhi has issued an advisory asking American citizens to be aware of additional security measures that may be imposed by authorities or disturbances in the temple town of Uttar Pradesh or elsewhere.

• 2 blasts rock Varanasi; 20 dead

"American citizens travelling throughout India should monitor news reports regarding any additional security measures that may be imposed by Indian authorities in Varanasi or elsewhere, or any demonstrations or other disturbances that may arise as a result of the bombings, particularly through the Holi religious festival," it said.

Giving details of the March 7 bombings in Varanasi and specifically mentioning that no foreigner had been affected in these, the advisory said security has been increased at many religious sites and popular tourist locations in the township and elsewhere in India.

With particular reference to Varanasi, it said although police officials have not imposed formal curfew there, "additional security measures implemented by local police could pose inconveniences to travellers wishing to travel around the city, as well as those wishing to arrive in or depart from the city by air, rail and road".

The embassy said, "Religious clashes in Lucknow are a further source of concern."