The bus mainly carried families on their way to spend a holiday at the Uludag ski resort.
The tour bus, belonging to Kartallar Gezi firm, reportedly hit trees on the roadside of the Eskisehir-Bursa highway.
A bus carrying mostly holiday-makers on a ski trip in Turkey has crashed into trees on the side of a road, killing 11 passengers and injuring 44 others, officials say.
Eskisehir Governor Ozdemir Cakacak and Provincial Police Chief Engin Dinckaza examined the scene.More news: JC Penney Company, Inc. (JCP) - Active Stock to Focus
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Officials said 46 people were injured in the crash, which happened in the Eskisehir area in the north-west of the country.
The driver and his assistant, who both sustained minor injuries, were taken into custody as part of the probe.
Last year, 7,300 people died in over 1 million accidents on Turkish roads, according to the Turkish statistical institute.
Ukrainians have not been killed or injured as a result of a road accident in Turkey.