From CNN:NEW DELHI, India (CNN) -- Serial bomb explosions ripped through India's remote northeastern state of Tripura on Wednesday, killing one person and injuring about 100, authorities said.
Kishore Ambuly, the top administrative official of the West Tripura district, told CNN that explosions occurred at four locations in the district capital of Agartala within a span of an hour.
Two marketplaces, one bus terminus and one residential colony were hit, he said.
He named no suspects, but said police were investigating all angles, including any possible involvement of tribal insurgent groups or cross-border militant outfits.
It is the second string of bomb attacks in India this week.
Two motorcycle bombs exploded in western India's Gujarat and Maharashtra states Monday night, killing four people and wounding several others, police said.
Previous attacks have been blamed on the Indian Mujahedeen group, which authorities connected to bombings in Gujarat in July, and courthouse bombings in Uttar Pradesh last November.