Turkey's top court ruled Thursday that Islamic head scarves cannot be allowed at universites because that would violate secularism.

The decision is a defeat for Prime Minister Recep Tayyip Erdogan's Islamic-oriented government, which tried to allow the scarves at universities as a matter of personal and religious freedom.

But the Constitutional Court verdict issued Thursday said constitutional amendments that were passed by Parliament in February violated secular principles.

The head scarf issue is an explosive one Turkey, where the government is locked in a power struggle with secular groups that have support from the military and other state institutions.

The verdict is likely to bode ill for the government. Turkey's chief prosecutor is seeking to disband the ruling party because it is "the focal point of anti-secular activities" in a separate case at the Constitutional Court. He has cited attempts to allow head scarves at universities as a case in point.

Many see the head scarf as an emblem of political Islam, and consider any attempt to allow it in schools as an attack against modern Turkey's secular laws.

There was no immediate comment from the government on the ruling. Deputy Prime Minister Cemil Cicek said the government would like to see the court's reasoning before saying anything.

A brief statement from the court said the amendments were annulled because they were in violation of some articles of the Constitution, including one that states that "The Turkish Republic is a secular state." and another that says that altering the secular nature of the state "cannot even be proposed."

Onur Oymen, a senior lawmaker of the opposition Republican People Party, said the verdict spelled the end such amendments.

"From now on, no one will be able to attempt to change the Constitution," Oymen told NTV television.

"This decision reminds the ruling party what it can do or it cannot do despite winning 47 percent of the votes," Husamettin Cindoruk, former parliament speaker, told NTV television. "This decision has set the boundaries and reshaped the state."

In February, Parliament passed constitutional amendments to allow head scarves to be worn at universities — but not in schools or state offices. The secular opposition appealed to the top court.

Turkey's 70 million people are predominantly Muslim. But secularists feared that lifting the ban at universities would erode Turkey's secular nature and create pressure on all female students to cover themselves.

Pious female students have been forced to remove their head scarves at the entrance to campuses. Some have attended classes wearing wigs.

Mustafa Kemal Ataturk, who founded modern Turkey after the collapse of the Ottoman Empire, banned religious attire in daily life. The ban has been vigorously enforced in public office and schools since a 1980 military coup.