Thane, Jan 10 (Agency) Four motorbike-borne men on Sunday opened fire at a jeweller shop located in Ambernath town of this district. The assailants, who came on two motorbikes, fired seven rounds at the shop at around 1340 hours. The incident left three persons seriously injured, police said, adding that the accused made an unsuccessful attempt to loot the jewellery shop. The injured have been rushed to the Ulhasnagar Central Hospital. A nakabandi or road checks has been enforced in the vicinity to trace the shooters, police apprised.