Athens, Dhu-AlHijjah 11, 1435, October 05, 2014, SPA -- At least four people were killed Sunday in a chain-reaction pile-up on a northern Greek highway when a commercial truck plowed into stalled traffic, dpa reported. "It was a horrible collision. The cars formed a formless mass," Greek Fire Chief Chryssanthos Athanassopoulos was quoted as saying by the ANA-MPA news agency. At least 35 vehicles, including three commercial vehicles, were involved in the accident, which took place between the cities of Veria and Thessaloniki. According to local reports, one lane of traffic was closed for maintenance at the time of the collisions. The truck driver who reportedly caused the accident was arrested. -- SPA 18:25 LOCAL TIME 15:25 GMT www.spa.gov.sa/w