At least 11 people have died and 46 more are injured after a Turkish intercity bus crashed into trees while travelling on a motorway, local officials have said.

The bus, which was making an overnight journey from the capital Ankara to the western city of Bursa, crashed in the region of Eskişehir amid good road conditions according to an official.

The road was empty and had no hazardous conditions, the official said, vowing that the causes would be made clear.

The passengers on the bus were mainly families with their children who were going to Bursa to spend the upcoming half-term at the popular Uludag ski resort nearby, according to the Dogan news agency.

It is unclear if any children were among those killed.

The two drivers, who received minor injuries, have been detained and prosecutors have launched an investigation, according to Dogan.

Turkey has a dire road safety record with over one million accidents in 2016 and 7,300 people losing their lives, according to official statistics.