Imphal, Nov 18 : A powerful bomb was detonated at Kairang, a Muslim dominated area, in Manipur though none was hurt in the explosion as it occurred early in the morning on Thursday, police said. Police said that explosion took place in front of the shop of one Mohammad Tolen in Imphal East District at around 4 a.m. on Thursday morning. No organisation has yet claimed responsibility of the blast. Police personnel led by senior officials immediately rushed to the spot and a search operation was on to nab the perpetrators. Security forces including Army and para-military Assam Rifles are on high alert in Manipur after the Saturday's deadliest terror attack in which an Assam Rifles Colonel Viplav Tripathi and four jawans of the para-military force were gunned down in Churachandpur district bordering Myanmar. The guerrillas of the People's Liberation Army (PLA) jointly with Manipur Naga People's Front (MNPF) militants, armed with sophisticated weapons, had also killed Tripathi's wife, their nine-year-old son in the ambush. After Saturday's bloodiest militant attack, the security forces recovered a large cache of powerful Improvised Explosive Devices, fitted with a mobile phone handset and digital watch, from three separate locations in Manipur. Months ahead of the assembly elections in Manipur, militant activities have increased in the northeastern state with the authorities having asked the security forces to intensify vigil in the sensitive, mixed populated and vulnerable areas. Elections to the 60-seat Manipur assembly are likely to be held in February-March next year along with Uttar Pradesh, Punjab, Uttarakhand and Goa. /IANS