Thousands of Indonesian security forces will be deployed at a rally this week against Jakarta’s Christian governor to prevent a repeat of violence that marred a protest earlier this month, police said Tuesday.

About 22,000 officials — mostly police and soldiers, as well as some paramedics — will be on the streets for Friday’s rally against governor Basuki Tjahaja Purnama, who has caused anger in the world’s most populous Muslim-majority country by allegedly insulting Islam.

Police said they expect at least 150,000 protesters to turn out for the demonstration against Purnama, who is also a member of Indonesia’s small ethnic Chinese minority.

Authorities named Purnama, known by his nickname Ahok, a suspect in a blasphemy investigation this month after Muslim groups demanded that he be prosecuted for allegedly insulting the Koran while campaigning for governorship elections.

The controversy is being seen as a test of religious tolerance in Indonesia, where minorities have increasingly come under attack. Some observers however say it is as much about politics, accusing the governor’s rivals of whipping up anger in a bid to reduce his support.

After a massive demonstration against Purnama on November 4 turned violent in its later stages, with one man dying as Muslim hardliners battled police, authorities are taking no chances ahead of Friday’s rally.

Police have restricted the area of the protest to a park around a major monument in downtown Jakarta and it will take place from 8:00 am (0100 GMT) to 1:00 pm.

On Tuesday national police spokesman Boy Rafli Amar detailed the number of security forces to be deployed and urged protesters not to bring any weapons.

“It’s forbidden to bring sharp weapons, like sharpened bamboo,” he told reporters, adding that at the earlier protest some people had used bamboo flagpoles to attack officers.

Several hundred people were injured in the protest violence, which saw demonstrators hurling missiles at police who responded with water cannons and tear gas.

The controversy began in September when Purnama accused his opponents of using a Koranic verse, which suggests Muslims should not choose non-Muslims as leaders, in order to trick people into voting against him.

Even though Purnama has been named a suspect, hardliners are now demanding that he be arrested before an expected trial.

The governor — who faces up to five years in jail if found guilty — has vowed that he will still contest the February election.