ATTOCK        -     Four persons including two real sisters died while one received critical injuries when an ambulance they were travelling by collided with a bus near Langrial, about 65-km off here on Thursday. According to the local police, the dead and the injured were shifted to the THQ Hospital Pindigheb. According to eyewitnesses, the accident took place due to overspeed and slippery road. The deceased included Robina Kausar d/o Behram Khan, Khalida and Abida both the daughters of Mian Khan, and Amir Ali s/o Banaras Khan.  Behram Khan who received multiple injures is reportedly in critical condition. All those died and injured were residents of Basal.