An Egyptian soldier on Wednesday was gunned down in the Sinai Peninsula in northeastern Egypt as voters cast ballots on the final day of the country’s presidential election.

An Egyptian soldier on Wednesday was gunned down in the Sinai Peninsula in northeastern Egypt as voters cast ballots on the final day of the country's presidential election.

Border guard Mohammad Kamel Aql was shot dead by unidentified gunmen while on duty in Rafah in North Sinai, army spokesman Ahmed Ali wrote on his Facebook page.

The Sinai Peninsula has been dogged by violence since last summer's ouster of elected president Mohammad Mursi, with militant groups targeting police and army personnel.

Wednesday's killing came as voters continued to cast ballots for a third and final day on Wednesday in Egypt's presidential election, in which former army chief Abdulfattah al-Sisi is facing off against leftist Hamdeen Sabahi.

The vote is the second step of an army-imposed transitional roadmap, which included a constitutional referendum in January. The plan will conclude with parliamentary elections later this year.

The winner of the polls will take over from interim president Adly Mansour, who was installed by the army almost 11 months ago following Mursi's ouster and subsequent imprisonment.