Five bombs exploded in quick succession in crowded markets and streets in India's capital New Delhi, killing at least 20 people and injuring 90 more.
The Indian Mujahideen Islamic militant group, which has claimed several major attacks in recent months, sent an email to television stations saying it was responsible for the blasts.
Police and witnesses said two bombs went off in dustbins in and around Connaught Place, a shopping and dining area popular with tourists and locals in the centre of the city.
Others exploded within minutes of each other in busy markets around the city.
Hundreds of people have been killed in a wave of bombings in India in recent years, mostly blamed on Muslim militants, with targets ranging from mosques and Hindu temples to trains.
In July, at least 45 people were killed when a series of bombs ripped through Ahmedabad, the main city of the western state of Gujarat. A day earlier, one woman died when eight bombs went off in the IT hub of Bangalore.
The failure to prevent the attacks has become an embarrassment for the Congress party-led coalition government, with elections less than a year away.
