Tens of thousands in Jakarta demand the resignation of its governor who they say committed blasphemy.

One person was killed as Indonesian police fired tear gas and water cannon to disperse tens of thousands of protesters who rallied to demand the resignation of the Christian governor of Jakarta for allegedly insulting the Quran.

At least seven people were injured in clashes between demonstrators and police, Jakarta police spokesman Awi Setiyono said on Friday.

An elderly man died, possibly from the effects of tear gas, said Setiyono, adding four civilians and three police officers were hurt.

Tens of thousands of protesters called for Jakarta’s governor to be prosecuted for blasphemy in the massive demonstration. A sea of protesters wearing white robes took to the streets in a huge show of force against Governor Basuki Tjahaja Purnama.

Indonesian police fired tear gas to disperse protesters near the presidential palace, local televison reported.

Some protesters threw plastic bottles at officers who had formed a barricade.

The protest was triggered by accusations that Purnama, better known by his nickname Ahok, insulted Islam by criticising opponents who used Quranic references to attack him ahead of an election in February.

Purnama apologised for the remarks, but his opponents have built a groundswell of support calling for his arrest and incarceration under Indonesia’s tough blasphemy laws.

“He is not Muslim but he humiliated the Quran,” protester Muhammad Said told Reuters news agency. “Don’t refer to anything in the Quran, especially interpreting it incorrectly… I call on God to jail him.”

The military warned it was ready to back 18,000 police officers deployed if things turned ugly. Helicopters flew low over the city and extra soldiers were stationed at key government buildings reinforced with razor wire and armoured vehicles.

Anger at Purnama, Jakarta’s second Christian governor and the first from the country’s ethnic Chinese community, spread beyond the capital with solidarity marches also held across Java and in cities as far away as Makassar in Indonesia’s east.

Protesters called for Purnama’s death as Friday’s turnout – estimated by police at 50,000 – eclipsed a similar protest last month that drew 10,000 chanting demonstrators to city hall.

The demonstrators, led by a group called the Islamic Defenders Front, chanted “God is greatest” and waved placards calling for Purnama to be jailed for blasphemy.

A white banner hung at an overpass was painted with red letters saying “Hang Ahok here”.

Police deployed 18,000 officers to the capital before the rally [Bagus Indahono/EPA]

Police are investigating the case against Purnama, who has apologised for his remarks, insisting he was not criticising the Quranic verse but those who used it to attack him.

President Joko Widodo this week met religious and political leaders to issue a unified call against violence, while police sought to ease tensions by holding prayer sessions and broadcasting calls for peace on social media.

Widodo, known popularly as Jokowi, pressed on with business on Friday despite the much-hyped protest, meeting cabinet ministers and inspecting a train project, his spokesman Johan Budi said.

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Indonesia is home to the world’s biggest Muslim population, where a vast majority practise a moderate form of Islam.

But the governor stoked religious tensions in September when he told a crowd they’d been “deceived” by his opponents who had used a Quranic verse to try to put them off voting for a Christian.

The governor – known for his tough-talking style – is hugely popular in other quarters for his determination to clean up Jakarta, an overcrowded, disorganised and polluted metropolis.

Purnama became Jakarta governor in November 2014, but was not elected to the post. He was deputy governor and automatically became governor after incumbent Widodo was elected Indonesian president.

Ethnic Chinese make up about one percent of Indonesia’s 250 million people, and they typically do not enter politics.