Guwahati: At least five people, including an infant, were killed and 12 others injured today in a powerful explosion at a crowded market place in Assam's main city of Guwahati.

A police spokesperson said the blast took place at the busy Mackhowa vegetable market around 7.50 a.m. "The bomb was probably strapped to a bicycle and kept near the entrance of the market. The blast was of a very high magnitude killing five people on the spot. The dead include an infant about six to seven months old," Rajen Singh, additional police chief of Guwahati city, told IANS.

He said at least 12 people were injured in the explosion. "The condition of at least four of the injured is critical with the victims receiving multiple wounds in their chest, face and abdomen," a doctor at the Guwahati Medical College Hospital said.

Police blamed the outlawed United Liberation Front of Asom (ULFA), a militant group fighting for an independent Assamese homeland since 1979, for the blast. In the past three months, the ULFA has carried out at least 24 bomb explosions in Assam killing about 20 people and wounding many more. The ULFA was also blamed for a string of attacks in January that killed about 80 people, 61 of them Hindi-speaking migrant workers.

New Delhi launched a massive military offensive against the ULFA after the strikes killing 55 rebels and arresting 553 more cadres since January.