Turkish police on Saturday forcefully broke up a student protest close to President Recep Tayyip Erdogan's new presidential palace, with one policeman punching a student, reports said.
Video footage showed police, wearing body armour, using pepper spray to break up the protest over the Turkish tuition system as the students tried to march towards the palace in Ankara.
A policeman was shown punching a demonstrator once in the neck and again in the face, as another officer grabbed him. "Why are you punching me?" the protester is heard asking.
Others are shown being roughly pinned down by police with their hands behind their backs and faces pushed into the tarmac.
Twenty-two student protesters were arrested, the private Dogan news agency reported.
The students had come to within 100 metres (330 feet) of the building, the Hurriyet daily said.
Erdogan's new presidential palace, which is surrounded by high gates and has tight security, is a hugely controversial project condemned by opponents as an authoritarian excess.
Pope Francis on Friday became the first significant foreign dignitary to visit the palace. With 1,000 rooms, it cost 1.37 billion Turkish lira ($615 million) to build.