An Egyptian court has voided a maritime border deal signed with Saudi Arabia that would hand over the control of two strategic Red Sea islands to Riyadh.

The agreement, signed in April, conceded Egypt's control of the strategic Tiran and Sanafir islands to Saudi Arabia, sparking angry protests in Cairo and other cities.

The ruling is a setback for President Abdel Fattah el-Sisi, who had asked Egyptians in a speech to end the controversy over the islands deal, which was announced during a visit to Cairo by the Saudi king.

The state has the right to appeal the ruling at a higher court, and the accord must also be approved by parliament.

Egyptians, who have considered the islands to be their land for decades, say Sisi is selling their territory with a humiliating concession to a wealthy ally. Critics also say the agreement violates the Egyptian constitution.

Egyptian courts have given jail terms to hundreds of people for taking part in the protests against the handover of the islands to the Persian Gulf kingdom.

The Tiran Island is located at the entrance of the Straits of Tiran, which separates the Red Sea from the Gulf of Aqaba.

Its strategic significance lies in the fact that it is an important sea passage to the major ports of Aqaba in Jordan and Eilat in Israel.

Sanafir Island is in the east of Tiran Island, and measures 33 square kilometers (13 square miles) in area.

Israel briefly took over the islands in late 1956, and once more between 1967 and 1982 following the Six Day War. The ownership of the two islands was transferred to Egypt in 1982, when Tel Aviv and Cairo signed the Camp David peace accords.

According to the daily Haaretz, Egypt informed Israel about its intention to give away the islands to Saudi Arabia and received Tel Aviv's blessing.

Israel reportedly expressed its approval of the give-and-take provided that freedom of navigation for Israeli ships through the area was guaranteed and all commitments undertaken by Egypt under the Camp David accord were honored.