Thirteen civilians including a child were injured, two of them critically, when a blast rocked Bongaigaon town in Western Assam on Monday.

Police informed that a programmable timer device which was planted by suspected United Liberation Front of Asom militants on a bicycle parked near the traffic police point at Paglasthan locality in the town, exploded at around 9.30 am.

Two persons, including the child, were critically injured in the blast and admitted in the government civil hospital in Bongaigaon. Four of the injured were small-time Hindi-speaking traders from the town.

Police cordoned off the area immediately after the blast and a combing operation has been launched. The army was rushed to the spot immediately after the blast

Meanwhile, Assam police has pasted posters of two senior ULFA leaders namely Hira Sarania and Akash Thapa, who are the suspected masterminds of all the explosions carried out by the outfit in Lower Assam areas including Guwahati city.

The police has sought public cooperation in getting information about the duo.

The police has promised a hefty cash award for accurate information and has promised to keep the identity of the informer a top secret.

Hira Sarania is the prime suspect in April 17 abduction of Food Corporation of India executive director Dr P C Ram from the heart of Guwahati. The senior FCI official has remained untraced since then.