A bus carrying dozens of Ukrainian citizens rolled off an embankment into a ditch in Poland, killing six people and injuring 41, Polish media reported on Saturday.
The accident occurred around midnight on the A4 motorway near the town of Jaroslaw, which is in southeastern Poland near the border with Ukraine.
TNV24, a private all-news station, reported that the bus had a Ukrainian license plate and was travelling with 57 Ukrainian citizens, including two drivers, who were travelling from Poland to Ukraine.
A large rescue operation early Saturday involved dozens of firefighters, paramedics and helicopters to transport the injured to hospitals.
There was no immediate cause given for the accident.
Many Ukrainians travel regularly for work to Poland, a European Union state on Ukraine's western border. Ukrainians fill gaps in the labour market in Poland, which has experienced fast economic growth in recent years.
