Tens of thousands of Muslims gathered Friday for a mass prayer at Istiqlal Mosque to discourage voters from voting for incumbent Jakarta governor Basuki Tjahaja Purnama, also known as Ahok, who is a Christian.

The gathering was held just a few days before the gubernatorial election, which will be held on Feb. 15. Crowd estimate was at 60,000 to 70,000 people, according to the Associated Press.

The protesters were not given permission to march through the streets of Jakarta, so they flocked around the national mosque for a prayer rally instead, where Muslim religious leaders called on the people to support Muslim candidates.

Ahok is running against two Muslim candidates: former education minister Anies Baswedan, who was removed from Pres. Joko Widodo’s cabinet, and Agus Harimurtri Yudhoyono, the son of former president Susilo Bambang Yudhoyono, who is one of Ahok’s staunchest critics.

Muslim hardliners had been campaigning against Ahok, who stood a good chance at winning the election, because he is a non-Muslim. Ahok belongs to the minority ethnic Chinese and is a member of the religious minority Christian church.

Despite his double minority background, he gained the reputation of working hard in cleaning up the streets of Jakarta, preventing flooding and fighting against corruption, which made him popular among the middle class voters.

Last year, he told fishermen at the Thousand Islands that his opponents were using the Quran to deceive people to not vote for him. His statement, recorded on video, caused an outcry among Muslims. They accused him of blasphemy, holding protests calling for his arrest.

Police eventually gave in and charged him with blasphemy. However, they did not arrest him, and he remained as candidate for Jakarta governor. He was also able to continue his campaign while the blasphemy trial was ongoing.

Ahok has maintained his innocence throughout his highly publicized trial, which the court eventually closed to media to protect the witnesses.

On Saturday, more than 20,000 police and military officers were deployed in Indonesia’s capital ahead of the Feb. 15 polls to ensure that public order is maintained.

"This is a celebration of democracy that is going to happen on the 15th and we need to ensure it happens in compliance with the laws," national police chief Gen. Tito Karnavian said, according to ABC.

The police chief had earlier warned religious leaders joining the prayer rally to steer clear of politics in their sermons.

“The difference between a sermon and a political oration is slim, so during your sermons please stay away from political nuance because the rules on that are clear,” Karnavian said.

Ahok’s trial and the Feb. 15 election are being viewed as Indonesia’s litmus test for religious tolerance. Muslim-majority Indonesia officially recognizes six religions: Islam, Protestantism, Catholicism, Confucianism, Hinduism and Buddhism.