As of 1 p.m., the official closing time for voting, no major incidents had been reported to the Jakarta Police or the Elections Supervisory Agency (Bawaslu).

Jakarta Governor Basuki “Ahok” Tjahaja Purnama voted at Polling Station 54 near his residence in the Pantai Mutiara housing complex in North Jakarta at about 8 a.m., along with his wife Veronica Tan and son Nicholas Sean.

Ahok wore a blue shirt, while Veronica donned a white kebaya and Nicholas a white T-shirt. In the first round of the election on Feb. 15, Ahok and his family had worn his campaign’s signature red-and-blue plaid shirts.

After exercising his political right, Ahok called on Jakartans to do the same. “I call on Jakartans to not be afraid to go to polling stations, because each vote could determine the fate of Jakarta's development," Ahok said.

"Whatever your choice is, you should go to the polling stations. If you encounter hurdles while voting, please report them to the officials."

Incumbent Basuki Tjahaja Purnama and his family cast vote for the Gubernatorial Election phase 2 at TPS 54, Pantai Mutiara, Pluit, Wednesday, April 19, 2017.(JP/Seto Wardhana)

(Read also: Jakarta runoff election 101)

Ahok’s rival, Anies Baswedan, meanwhile, voted in Lebak Bulus in South Jakarta. The former education and culture minister and his family arrived at the polling station at 11:00 a.m., three hours later than scheduled.

They were welcomed by dozens of volunteers and residents, who recited prayers as well as salawat (religious chants) for him. “Whatever the result is, we leave it to God. We are ready to win and to lose,” Anies said.

Hard-line Islamic groups have fomented sectarian sentiment against Ahok, a Christian of Chinese descent, since last year through a series of major rallies in the capital. Many of those who took part in the rallies are not from Jakarta.

The groups have announced to mobilize thousands of Muslims through a mobile application called Tamasya Al-Maidah (Al-Maidah Tour) to come to Jakarta and “guard” the city’s 13,032 polling booths against fraudulent activities.

Al-Maidah is a chapter in the Qur’an that contains a verse often used by conservative Muslims to urge Muslims not to vote for political leaders of another faith.

The National Police, however, have banned citizens from participating in the Al-Maidah Tour, saying it could trigger public unrest.

Al-Maidah Tour participants reportedly planned to gather at Istiqlal Mosque, but an official at the mosque, Abu Hurairah, told kompas.com that as of Wednesday afternoon, there had been no request for a permit from the organizers or the “tour.”

Islam Defenders Front (FPI) leader Rizieq Shihab, a leading figure behind the anti-Ahok movement, said the election would be held fairly and transparently, so that the results did not lead to problems. “If the election is just and fair, God willing, the outcome will not cause problems,” he said, as quoted by kompas.com on Wednesday.

Police deployed 66,000 officers to secure the election. As many as 2,400 Indonesian Military personnel from the Jakarta Military District Command (Kodam Jaya) and the West Java and Banten Military District Command (Kodam Siliwangi) are also set to be deployed in the event of an emergency. (dis/ary)