Head of the Israeli army's planning directorate has traveled to Cairo in the wake of the killing of several Egyptian military personnel during an attack by Israeli forces. Major General Amir Eshel arrived in Egypt's capital, Cairo, on Monday, and discussed the security agreements signed between Tel Aviv and Cairo with Egyptian officials, Israel's Hebrew language Maariv newspaper reported. On Thursday, the Israeli air force killed five Egyptian border guards in an attack in the vicinity of Egypt's border crossing with the Palestinian enclave of the Gaza Strip. Israeli Defense Minister Ehud Barak on Saturday apologized for the deaths, saying that he has ordered "a joint investigation with the Egyptian army to clarify the circumstances of the incident." He made the remarks hours after Egyptian state television announced that Egypt had "decided to withdraw its ambassador to Israel until there is an official apology." Egypt has also demanded that Israel halt its deadly airstrikes on the impoverished Gaza Strip. Israel launched its latest military airstrikes on the Gaza Strip on Thursday shortly after eight Israelis lost their lives in assaults that targeted two buses and a military vehicle near Eilat in southern Israel. The Israeli offensive claimed the lives of at least 16 Palestinians and injured more than 45 others, including children. The attack that killed the Egyptian officers has escalated tension between Cairo and Tel Aviv. Egypt was the first Arab country to sign a peace treaty with Israel in 1979, but the situation has changed drastically since Egyptian dictator Hosni Mubarak was deposed in February, and a number of Egyptian political parties are now calling for changes to the peace treaty.