Following is a chronology of some of the major attacks in India in the past five years:
March 13, 2003 - A bomb attack on a commuter train in Mumbai kills 11 people.
August 25, 2003 - Two car bombs kill about 60 in Mumbai.
August 15, 2004 - A bomb explodes in the northeastern state of Assam, killing 16 people, mostly schoolchildren, and wounding dozens.
October 29, 2005 - Sixty-six people are killed when three blasts rip through markets in New Delhi.
March 7, 2006 - At least 15 people are killed and 60 wounded in three blasts in the northerly Hindu pilgrimage city of Varanasi.
July 11, 2006 - More than 180 people are killed in seven bomb explosions at railway stations and on trains in Mumbai that are blamed on Islamist militants.
September 8, 2006 - At least 32 people are killed in a series of explosions, including one near a mosque, in Malegaon town, 260 km (160 miles) northeast of Mumbai.
February 19, 2007 - Two bombs explode aboard a train heading from India to Pakistan; at least 66 passengers, most of them Pakistanis, burn to death.
May 18, 2007 - A bomb explodes during Friday prayers at a historic mosque in the southern city of Hyderabad, killing 11 worshippers. Police later shoot dead five people in clashes with hundreds of enraged Muslims who protest against the attack.
August 25, 2007 - Three coordinated explosions at an amusement park and a street stall in Hyderabad kill at least 40 people.
May 13, 2008 - Seven bombs rip through the crowded streets of the western city of Jaipur, killing at least 63 people in markets and outside Hindu temples.
July 25 - Eight small bombs hit the IT city of Bangalore, killing at least one woman and wounding at least 15.
July 26 - At least 16 small bombs explode in Ahmedabad in the state of Gujarat, killing 45 people and wounding 161. A little-known group called the "Indian Mujahideen" claims responsibility for the attack and the May 13 attack in Jaipur.
September 13 - At least five bombs explode in crowded markets and streets in the heart of New Delhi, killing at least 18 people and injuring scores more. The Indian Mujahideen again claim responsibility.
October 30 - Terror struck the hub of North-East when over a dozen blasts on Thursday ripped through commercial areas of the capital and three other districts, killing 56 people and injuring 350 others.