Tiruchy: Three persons were killed on the spot and seven others, four of them women, were injured when a speeding omnibus rammed their car near Samayapuram, on the Tiruchy-Chennai national highway, Monday midnight. Police said Pandiyan (49) of Karambakudi, in Pudukkottai district, along with 10 others, including his family and relatives, was proceeding to Samayapuram temple after worshipping in a few temples in Thanjavur district. Their driver, instead of proceeding to the service road leading to Samayapuram temple, by mistake, took the Tiruchy-Chennai national highway bypass road. Police registered a case against omnibus driver Ajitkumar of Ramanathapuram district and are investigating. Due to the mishap, vehicular traffic on the Tiruchy-Chennai national highway was paralysed for some time.