The decision at the Helsinki summit to recognise Turkey as a candidate for European Union membership has prompted nationwide demonstrations against a ban on the wearing of religious headscarves in universities.
The country's high court last week ruled that a university had the right to ban women who wear headscarves.
The protest was largely peaceful, although in Istanbul police arrested more than 150 demonstrators following attempts by thousands of protesters to form a "human chain" across part of the city.
Police authorities said the
protest was illegal because the governor of the city had not granted permission for the protest.
One protester said: "A state without human rights cannot enter the EU.
"Anyway, we have only been accepted as a candidate and we may not be able to become a member because of this issue."
Turkey's human rights record is a stumbling block to its aspiration to membership, although the EU has been largely indifferent
to the banned Islamic students.
The government, along with the country's universities authority, has pledged to continue to enforce the ban. It argues that the headscarves are being used as a political tool to undermine the secular state.
Kemal Guruz, head of the university authority, said: "There will be no change in policy."
The ban remains contentious, especially within the country's Islamic movement.
In the past few months the government has increasingly clamped down on the demonstrations.