At least three people were killed and seven others injured in a pipeline explosion in Taiyuan, capital of north China's Shanxi Province, on Saturday, Xinhua reported. The explosion occurred at 11:18 a.m. and blew off road surface in the Yingze South Street, said Geng Yanbo, vice mayor of Taiyuan. The casualties were guests to a wedding banquet at a nearby hotel and migrant workers who were paving the road at the time of explosion, said the vice mayor. One person died on the spot while the other two died later from injuries in the hospital. The seven injured people are still receiving treatment in hospital. Witnesses accused the wedding undertakers of lighting firecrackers, which ignited the blast of gas pipeline underground. But the wedding undertakers said the wedding ceremony had not started when the explosion took place. They said that the workers might accidentally cut the gas pipeline and triggered the blast. The gas pipeline was confirmed to be intact and the pipeline that exploded did not belong to the gas company, either. Investigators were not sure what triggered the blast. The investigation continues. Police have detained the wedding ceremony undertakers and the people in charge of the road paving project.