Security has been heightened at many important places, tourist spots and government installations across Uttar Pradesh following an IB alert of a potential threat by terrorists, officials said on Sunday. Additional security has been deployed at the Taj Mahal, in Agra the biggest draw for foreign and domestic tourists.Officials informed that 36 extra commandoes have been deployed at the Taj Mahal, on the outer periphery, in and around the entry points. Other than this, CISF personnel who guard the world famous monument of love, have also been alerted on the possibility of a terror attack, a senior home department official informed.As the festival season is underway and important festivals like the Durga Puja, Dusshehra and Muharram are on the anvil, security has also been beefed up important cities like Lucknow, Agra, Kanpur, Moradabad, Bareilly, Meerut, Muzaffarnagar, Varanasi and Allahabad, a police official said.