The US on Monday issued a travel warning for its citizens visiting Pakistan, Afghanistan and Bangladesh, and said extremist elements were also "active" in India.
"The US government assesses terrorist groups in South Asia may be planning attacks in the region, possibly against US facilities, citizens and interests. US citizens should avoid travel to Afghanistan, as no region in the country is immune from violence," the State Department said in its worldwide caution.
"A number of established terrorist organisations, indigenous sectarian groups, and other militants pose a danger to US citizens in Pakistan.
"Extremist elements are also active in India, as outlined in a recent emergency message. Terrorists have hit a wide variety of targets and institutions in Bangladesh," it added.