Patna, Dec 26 : At least six labourers were killed and many others seriously injured after boilers at a noodle-making factory in Bihar's Muzaffarpur district exploded. The explosion took place on Saturday night at 10 p.m. and was so intense that its noise was heard 5 km away from the spot. Due to impact of the explosion, an adjoining flower mill was destroyed and two labourers sleeping inside also sustained injuries. The factory is located in the Bela Industrial area of Muzaffarpur. While a rescue operation is still underway to remove the debris, sources have said that more than 10 bodies are trapped inside the factory. Jayant Kant, Muzaffarpur Senior Superintendent of Police, who visited the spot, said: "We have recovered six bodies from the debris so far. Besides, five persons also sustained injuries and are admitted in the Sri Krishna Medical College and Hospital. "The rescue operation is currently underway. Fire fighters and police personnel are removing the debris. The exact number of deaths is not ascertained yet." /IANS