Voters in Egypt have begun going to the polls for a presidential election. Incumbent Abdel Fattah el-Sisi is widely expected to win his third term.

The three-day voting period began on Sunday. Voters were seen casting their ballots at a heavily-guarded polling station in Cairo.

The leaders of three political parties are challenging Sisi in Egypt's fourth presidential election since the 2011 Arab Spring prodemocracy movement.

The movement ended President Hosni Mubarak's 30-year rule. An election led to the inauguration of an Islamist government, but it was deposed by a de facto military coup.

Former military officer Sisi has served two terms as president and has consolidated his autocratic power base.

Egypt has been facing inflation of more than 30 percent and the decline of its currency, but these issues have not become major points of the election campaign.

Sisi has been raising his international profile, working as a mediator in the Israel-Hamas conflict.

One voter in Cairo said security is his top priority.

The election results are scheduled to be announced on December 18.