A delegation of Hamas leaders are in Egypt, seeking to patch up relations that soured with the 2013 overthrow of Egyptian president Mohamed Morsi.

Gaza security sources told AFP that Mahmoud Zahar, Khalil al-Haya, Imad al-Alami and Nizar Awadallah passed through the southern Gaza Rafah terminal, the only crossing point with the enclave not controlled by Israel, on Saturday.

They were heading to Cairo for talks with intelligence chiefs on relations between the sides.

Hamas, which rules Gaza, has its origins in the Muslim Brotherhood movement which is outlawed in Egypt.

Last week, Egypt's Interior Minister Magdy Abdel Ghaffar said both organisations were involved in last year's assassination of the country's top prosecutor, a claim both groups have denied.

A leader in Hamas told the pan-Arab newspaper al-Hayat that the delegation will discuss ways to enhance bilateral ties and the opening of the Rafah border crossing with Egypt in order to allow Palestinians in Gaza to travel.

Additionally, the two sides will discuss Egyptian accusations of Hamas supporting "terrorist activities" in the Sinai Peninsula; the assassination of Egypt's prosecutor last year; and the disappearance of the four members of the al-Qassam Brigades, the military arm of Hamas, who were kidnapped in the Sinai after entering Egyptian territory through the Rafah crossing a few months ago.

Former army chief Abdel Fattah al-Sisi, who deposed Morsi, won presidential elections in 2014 on a pledge to wipe out Islamist militants.

Egypt has largely kept its border with Gaza closed since 2013 and has destroyed hundreds of Palestinian tunnels under the frontier used to smuggle commercial goods, cash, people and, allegedly, weapons.