An unidentified explosion in a vehicle on Syria's Damascus-Homs highway on Monday caused casualties, state media reported, while a government source told AFP that three people were killed. State news agency SANA said that "an explosion took place inside a car on the Damascus-Homs road in the Al-Qastal area", adding that emergency workers removed "the bodies of victims", while authorities launched an investigation. A government source told AFP on condition of anonymity that three people were killed.