ULFA militants on Sunday stepped up violence in upper Assam by exploding three powerful bombs in three places killing six persons and injuring at least 29 others.
Official sources said here that two persons were killed when a powerful bomb planted by the ULFA on a motorcycle near a cinema hall at Uchumati in Doomdooma town in Tinsukia district exploded.
Fourteen persons who were nearby were injured in the blast.
In the second blast that occurred near Devipukhuri Tinali in Tinsukia town at around 5.45 pm near an electric transformer, two persons were killed and 17 injured.
Two of the injured succumbed to their injuries in the Assam Medical College Hospital at Dibrugarh.
ULFA ultras also exploded a bomb on an Assam Gas Company pipleline causing extensive damage.
A huge fire engulfed the pipeline and senior officials have rushed to the spot.
Fire extinguishers have been deployed to douse the flame.