Seven persons were arrested on Thursday in lower Assam's Nalbari district for suspected involvement in the October 30 serial bomb blasts in Guwahati which killed 85 persons.
Five others had been arrested earlier.
The seven were arrested from the Dhomdoma area in the Nalbari district and had been handed over to the Guwahati police for interrogation, district Superintendent of Police Jitmol Doley said.
A Special Investigation Team, formed to probe the incident, would be going to Nalbari for investigation, Doley said.
Immediately after the explosions, two prime accused -- Muzamul Haque and Anwarlul Haque -- were arrested from Lakhimpur on Tuesday following clues gathered from five persons detained the day before.
The police said the prime accused duo were involved in a car theft racket and in duplicating the names of the owners of the vehicles which were used for the blasts in Guwahati and Bongaigaon.