Plovdiv. Four students have been killed in a road accident with occurred on the road Bachkovo-Asenovgrad at around 1.30 pm. A BMW car with Plovdiv license plate has fallen from a bridge in Chaya River. The four youths are aged 22. They are two boys and two girls. The youths have been returning from a party in Rhodope mountain resort. Forensic medics announced that the death was caused by drowning or a blow. Reasons for the incident have been investigated.