Voting began on Sunday in a presidential election in Chad in which incumbent Idriss Deby is favorite to win a fifth term and extend a tenure that began in 1990.

Deby's main electoral argument is that only his government can take the necessary measures to guarantee stability in a region where Islamist militant group Boko Haram and al Qaeda affiliates have staged a series of attacks.

Chad has one of the region's most capable militaries and has played a key role in efforts backed by the West to combat Islamist militants in several countries.

"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.

Deby faces 13 challengers including opposition leader Saleh Kebzabo who argues that Chad needs change, though Deby has an advantage through his effective control of state media as well as the institutions of state and local administrations.

"I got up early to come and vote because we want change," said Mathieu Madjitulngar, an unemployed man queuing at a polling station in a suburb of the capital.