A spokesman for Lashkar-e-Taiba denied any role in the bombings of the crowded trains and train stations in Mumbai. He condemned the attacks, describing them as "inhuman and barbaric acts".

Another leading Kashmiri group, Hizb-ul-Mujahideen, denounced the bomb attacks as "outrageous." Its spokesman said in Islamabad, "Attacks on civilians are not part of our manifesto. We never carried out such attacks nor will allow anyone to do so."

Security sources in India said that the seven synchronised bombings were likely to have been carried out by militants connected to one or more of the dozens of armed Kashmiri separatist groups, according to the Guardian.

Mumbai, Indian financial capital, suffered similar serial blasts in 1993 that included an attack on the stock exchange, killing more than 250 people.

Kashmir is divided between India and Pakistan and both countries claim the region in full. The two countries have fought two wars over the Himalayan territory where more than 45,000 people have been killed since 1989.