Turkey’s prime minister Recep Tayyip Erdogan said voters have approved changes to a military-era constitution in a referendum widely seen as a vote of confidence for his government.

Erdogan said on Sunday that the constitutional amendments passed with 58 percent of the vote in favor.

The government says the changes are a key step in Turkey’s path to full democracy, while the opposition claims the reforms will shackle the independence of the courts.

The referendum had become a battleground between the Islamic-oriented government and traditional power elites that believe Turkey’s secular principles are under threat.

The date evoked Turkey’s traumatic past. Sunday was the 30th anniversary of a coup that curbed years of political and street chaos but led to widespread arrests, torture and extrajudicial killings, and Kurdish militants launched a rebellion a few years later that continues today. The military’s long shadow over Turkish politics has begun to wane only in the last few years.

The civilian government says the amendments fall in line with European Union requirements for membership, partly by making the military more accountable to civilian courts and allowing civil servants to go on strike. The opposition, however, believes a provision that would give parliament more say in appointing judges masks an attempt to control the courts, which have sparred with Erdogan’s camp.

The military and the court system, including the Constitutional Court, have sought to uphold the secular legacy of Mustafa Kemal Ataturk, who founded Turkey in 1923, and the ruling Justice and Development Party has been accused of plotting to undo those principles.

The ruling party, whose reforms have won backing from the EU, says the hardline emphasis on secularism and nationalism must be updated to incorporate democratic change, including religious freedoms. It lost a battle in 2008 when the Constitutional Court struck down a government-backed amendment lifting a ban on the wearing of Muslim headscarves in universities.

The constitutional amendments would also remove immunity from prosecution for the engineers of the 1980 coup. Kenan Evren, the military chief who seized power and became president, is 93 and ailing.

Earlier, in unrest related to the referendum, masked protesters calling for a boycott hurled gasoline bombs at police and threw stones at a school used as a polling station in an Istanbul neighborhood. Police responded with pepper gas and chased protesters down side streets.

Similar protests were reported in the Mediterranean city of Mersin and the nearby town of Akdeniz. In the southeastern province of Batman, six police officers were injured and four people were detained in a protest linked to the vote.