Suspected separatist militants triggered an explosion in a crowded market of a northeastern Indian city on Thursday, wounding at least 18 people, police said according to AP. Several of the injured were in serious condition, said Rajen Singh, a police officer in Gauhati, the capital of Assam state. The bomb was planted on a bicycle, Singh said. The explosion in Athgaon neighborhood _ one of Gauhati's main shopping hubs _ occurred when the place was teeming with evening shoppers. There was panic in the city after the blast. No group immediately claimed responsibility for the explosion, but Singh blamed the blast on the United Liberation Front of Asom, or ULFA, which has been fighting for Assam's separation from India. ULFA rebels have stepped up violence after the Indian government called off peace talks and a temporary truce on Sept. 24 and resumed a military offensive against the group. Talks collapsed after the government refused to accept the rebels' demand that it release five detained leaders. Since then, at least 30 people have been killed and more than 100 wounded in violence blamed on the rebels. The rebels accuse the federal government in New Delhi of pursuing such policies that have led to exploitation of the region's resources, while bringing little benefit to local residents.