Facing criticism over incomplete Commonwealth Games venues, government has decided to crack the whip on officials involved with the projects making them "directly responsible" for any further delay.

An accused in the 2008 serial blasts in the national capital was on Monday arrested by the Anti-Terror Squad of the Uttar Pradesh Police from Azamgarh district, a senior officer said in Lucknow.

Ahead of the Republic Day, the Centre has asked seven states, including Maharashtra, Karnataka and Delhi, to remain fully alert to prevent any attempt by terrorists to disturb peace.

After its satellite townships, it is the national capital which is aspiring to become an information technology hub with the Delhi government focusing on setting up service and IT-based industries in New Delhi.

Large parts of North India, including Delhi, plunged back into darkness on Saturday night as the regional electricity grid collapsed due to dense fog, hours after it was restored, bringing to several trains in the region to a standstill.