A powerful bomb planted by militants exploded in crowded Maligaon area, near Kamakhya hills, in Guwahati on Friday, killing at least two and injuring five persons. The blast took place at around 6.15 pm near a bazar, Assam police spokesperson Jayashree said. The bomb was planted on a bicycle near a market. The injured have been taken to the railway hospital in the city. So far, no outfit has accepted the responsibility for the blasts. Assam had been rocked by serial blasts for the past several months and in the last one on New Year's Day three blasts in the city claimed five lives.