Hardline Muslim leader among five arrested in Indonesia ahead of mass anti-Ahok protest

Five people, including a leader of a hardline Islamist group, have been arrested in Indonesia for suspected treason. The arrests come ahead of mass demonstration by thousands of Muslims on Friday (31 March) who are calling for Jakarta's Christian governor to be sacked over an alleged blasphemy case.

The demonstrations are being held as political and religious tension have flared up across the Indonesian capital city, ahead of the second and final round of the governor election in Jakarta, which is scheduled to take place on 19 April.

Muhammad al Khaththath, the leader of the Islamic People's Forum, which has organised the latest rally, and four other were arrested early on Friday, Jakarta police spokesman Argo Yuwono told local media.

"We are charging them with conspiring to commit treason," Yuwono said. "There were several findings, including a plan to occupy the Indonesian parliament."

Security has been beefed up across the city, with police and military forces cordoning off roads leading to the presidential palace as thousands of protesters rally at Jakarta's grand mosque.

The protest is the latest in a series that is reported to have tested the ethnic and religious tolerance in the world's most populous Muslim country. Around 20,000 people from various groups are expected to attend the demonstrations, police said earlier this week, according to Reuters.

Muslims are demanding that incumbent governor Basuki Tjahaja Purnama, also known by his Chinese name Ahok, be arrested. He is on trial for blasphemy after being accused by hard-line Muslims of insulting the Islamic holy book, Quran.

They alleged that Purnama insulted Islam and dishonoured the Quran by quoting a verse during his campaign in September to boost his chances of winning the governor's post for a second term. Although Purnama apologised for passing offending remarks, he denied committing blasphemy.

If found guilty, he could face jail of up to five years.

Purnama faces a tight race with rival Anies Baswedan, a Muslim candidate and former education minister, in Jakarta's gubernatorial race.