At least three personnel of government owned construction company, Frontier Works Organisation (FWO) were killed and seven others injured when a vehicle overturned here in the wee hours of Monday. Sources said that an over speeding vehicle of FWO turned turtle near Gwargo area of Panjgur due to bursting of tyre resulting in death of three FWO men on the spot and leaving seven others injured. The bodies and wounded were shifted to a local hospital where according to hospital sources condition of some injured personnel was critical.