People in Chad have started casting their ballots in a presidential election, with incumbent Idriss Deby widely expected to win a fifth term in office.

Polling stations opened at 07:00 a.m. local time (0600 GMT) on Sunday and will close at 6:00 p.m. local time (1700 GMT), with some six million Chadians eligible to take part in voting.

Deby, who came to power through a military coup in 1990, has maintained tight control over state institutions and is involved in counter-terrorism operations in the region.

The Chadian military is contributing troops in the regional fight against the Boko Haram Takfiri terrorist group, which has launched attacks on Chad from the Nigerian border.

“We came to vote for the president to guarantee peace in our country. Around us in the neighboring countries there are too many problems,” said civil servant Fatima Zara as she lined up to vote in Sunday’s poll.

Deby, however, faces unprecedented dissent at home, where demonstrations have been banned and opposition leaders have been imprisoned over the past few weeks.

In February, the alleged gang rape of the teenage daughter of an opposition presidential candidate led to angry protests. Mahamat Brahim Ali stood down in favor of Deby at the last minute.

Among Deby’s other 12 challengers, the most prominent is Saleh Kebzabo, the leader of the National Union for Development and Renewal group.

He served in ministerial positions under President Deby between 1993 and 2001. The politician ran against Deby in the 1996 and 2001 presidential elections, but finished third on both occasions.

Kebzabo has promised to promote national unity and education in the oil-rich African country if he wins the presidential race.

“I got up early to come and vote because we want change,” said Mathieu Madjitulngar, an unemployed man queuing at a polling station near the capital, N’Djamena.

Joseph Djimrangar Dadnadji, who served as premier between 2013 and 2015 is another high-profile candidate in Chad’s presidential poll.

Half of Chad’s population of 13 million live below the poverty line despite oil revenues.