Top Indonesian officials on Monday called for calm ahead of a planned protest by hardline Muslim groups that has fueled concern over religious and ethnic tension in the run-up to next year's election of the capital's governor.



Thousands of hardline Muslims are expected to take to the streets on Friday to protest against the incumbent, who is a Christian and the first ethnic Chinese in the job, after he made comments about the Islamic holy book, the Koran.



But political, security, and religious figures in the world's largest Muslim-majority nation have urged demonstrators to protest peacefully.



"I, along with religious and political figures, have been cooling sentiment...because rivalries exist, but after elections, we must stand together to build the nation," President Joko Widodo told a joint news conference with top opposition official Prabowo Subianto.



Earlier on Monday, in response to a question about the planned protest, Widodo said, "Protesting is a democratic right and the government guarantees the right to express opinions, but also prioritizes public order."



Protest organizer the Islamic Defenders Front, a small hardline group, is known for violent protests and attacks against minorities since it was formed in 1999.



It has also frequently protested against Jakarta governor Basuki Tjahja Purnama, known locally as "Ahok".



The group made no immediate comment in response to the officials' call for calm.



The government will deploy thousands of police and military personnel to provide security on the day of the protest.



The post of Jakarta governor is a prestigious role that is sometimes seen as a stepping stone to higher political office.



President Widodo served as Jakarta governor for 1-1/2 years before running for, and winning, the presidency in 2014.



Purnama, who took over for Widodo, has gained a reputation as a tough reformer, but Muslim groups in several cities have marched against the Protestant governor, urging Jakarta residents not to re-elect him in February.



The governor has the backing of Widodo and his ruling party, however, and remains a frontrunner in opinion polls.