Guwahati, Apr 6 At least one person died and four others injured in third bomb blast of the day in Assam's Dhubri district near the Indo-Bangla border at 7:16 evening.

Earlier in the day, two incidents of bomb blasts were reported in different places of the State-Maligaon area in Guwahati city and Dhekiajuli, an industrial city of Sonitpur District.

Seven people had been killed and over 61 others left wounded in the twin bomb blasts during the daytime.

The United Liberation Front of Asom (ULFA) is suspected of behind the blasts.

The three blasts hold significance as they have come just ahead of Prime Minister Dr. Manmohan Singh's scheduled visit to Assam on Tuesday.

These blasts have also been carried out a day ahead of the ULFA's 30th 'Flag Raising Day'.

Meanwhile, Union Home Secretary Madhukar Gupta has spoken to Assam Chief Secretary P. C. Sharma and asked him to strengthen security arrangements in Guwahati and other places.

According to PMO sources, Manmohan Singh's visit to the State remains unchanged. (ANI)