Guwahati, May 14 : At least one person was killed and three others injured in a grenade attack in eastern Assam's Tinsukia district on Friday, police said. Police officials said that two motorcycle-borne miscreants threw the grenade in front of a hardware shop at Tingrai market in Digboi town. One Sanjib Sen, 25, was killed and three others sustained injuries in the blast. The injured were shifted to a hospital. Security forces led by senior officials have rushed to the market and have cordoned off the area and launched a search operation to nab the culprits. Further details are awaited. Assam Chief Minister Himanta Biswa Sarma condemned the grenade attack and asked the Director General of Police Bhaskar Jyoti Mahanta to probe the incident. Assam's Chief Minister's Office (CMO) tweeted : "CM Himanta Biswa Sarma expressed concern over the grenade blast at Tingrai Market in Digboi and asked DGP to deal with the incident sternly and nab the miscreants at the earliest." Earlier this week, on Tuesday, a 12-year-old boy was killed in a grenade blast in the same district. Tinsukia's Superintendent of Police Vaibhav Nimbalkar had said that the grenade, which was lying on the roadside, suddenly exploded when Sujoy Hajong was riding his bicycle at Hajong village under Jagun police station area. /IANS