At least three people were killed when suspected separatist militants set off three bombs in the main city of India's troubled northeastern Assam state on Thursday, police said.
The blasts wounded 27 people, with the death toll likely to rise, police said.
The first bomb was found in a dustbin in a heavily populated residential area, but went off at around 1.45 pm (0815 GMT) before a disposal squad could defuse it, police said.
Two other devices exploded in the late afternoon, one of them near a crowded shopping mall, police said.
No one immediately claimed responsibility for the attack.
Police pointed the finger at the United Liberation Front of Asom (ULFA), the major separatist group in the oil- and tea-rich state often blamed for attacks, for being behind the blasts.
"We suspect the ULFA is behind these explosions," Guwahati's deputy inspector general of police, G.P. Singh, told Reuters.
India's Home Minister Palaniappan Chidambaram was due to visit the state for a security review on Thursday.
The ULFA is among more than two dozen armed groups in India's northeast which are either fighting for an independent homeland or more political autonomy.
They accuse New Delhi of plundering the region's mineral and forest resources, neglecting the local economy and giving them back nothing in return.