Thousands of hardline Muslims turned violent during a protest calling for the prosecution of Jakarta’s Christian Governor over comments he made about the Quran, reports the BBC.

An estimated 50,000 demonstrated at a largely peaceful rally in the Indonesian capital on 4 November after the Governor Basuki Tjahaja Purnama said that Islamic groups using a passage in the Quran to urge people not to support him were deceiving voters, who go to the polls in February in the world’s most populous Muslim nation.

Purnama apologized for the comment but a formal complaint was made and he is now under investigation by the police.

When Purnama was elected governor in 2014, the Islamic Defenders Front – the main group behind the protest – said that a Christian should not govern a Muslim-majority city. Purnama is Jakarta’s second Christian governor following Henk Ngantung in the 1960s. Indonesia became independent in 1945. There were hopes that Indonesia would clamp down on Islamic extremism when Joko Widodo – Purnama’s predecessor and a progressive Muslim – became the country’s president in 2014.