Three demonstrators, a journalist and a police officer had been injured, the Dogan News Agency reported Wednesday.
The province of Eskisehir has been following demonstrations in Istanbul over plans to demolish Gezi Park near Taksim Square.
European criticism of the handling of the demonstrations has been dismissed by Prime Minister Recep Tayyip Erdogan.
Erdogan said he does not recognize the European Parliament or a resolution that condemned Turkey's harsh crackdown on the protesters.
Turkey's justice minister canceled plans to attend upcoming meetings of the European Parliament and the European Commission in Brussels, Today's Zaman reported.
At the same time, a European Parliament delegation called off its planned trip to Turkey.