A series of five bomb explosions by suspected ULFA-Independent militants rocked upper Assam's Charaido and Tinsukia districts this morning as the state celebrated the country's 70th Independence Day.

There was no casualty or injury in any of the explosions, police said.

A blast was reported at an abandoned place beside an interior road at 7.40 AM at a place under Tengapukhari outpost in Charaideo district, Superintendent of Police A P Tiwari said.

The militants had apparently placed the bomb under the ground, Tiwari said.

In Tinsukia district, four other explosions were triggered by the insurgent outfit. An improvised explosive devise (IED) went off near Indira Gandhi School at Laipuli area on the outskirts of district headquarters of Tinsukia town at 7.15 AM, the officials said.

This was followed by another blast in line no.6 of Badlabhata Tea Estate in Doomdooma area where the third IED was also set off at Masuwa, they said.

The fourth one exploded at Gamtumati in Philobari area where ULFA-I militants on August 12 night had shot dead two persons and injured six others in indiscriminate firing at Bahbon village.

Yesterday, a powerful 4 kg IED was recovered at Mukum based on interception of an ULFA-I message, officials said.

On August 5, 14 people were killed and over 20 injured by NDFB (Songbijit) insurgents at Balajan in Kokrajhar district.

Security measures have been tightened across Assam and patrolling by security forces intensified, the police added.