Egyptian President Abdel-Fattah El-Sisi has ordered the Egyptian army to transport 500 tons of food and medical supplies to aid Palestinians under attack in the Gaza Strip, Al-Ahram's Arabic website reported.

A statement issued by the Egyptian military said diplomatic efforts by Egypt are ongoing to "stop the Israeli aggression on the Gaza Strip, under the direction of President Abdel-Fattah El-Sisi."

Israel has been subjecting the coastal enclave to airstrikes for the last four days. At least 100 Palestinians have been killed by the military offensive, many of them children.

Egypt's foreign ministry condemned earlier what it said was Israel's excess use of military force and the collective punishment policy it is adopting against the Palestinians.

"Egypt rejects Israel's irresponsible escalation in the occupied Palestinian lands amid its excess and unjustifiable use of military force and the subsequent bloodshed of innocent civilians," a statement by the Egyptian foreign ministry released on Friday read.

Egyptian activists have begun to collect medical supplies for Palestinians, to be transmitted via convoy to Gaza.

Egyptian hospitals received 11 injured Palestinians on Thursday; the small number drew criticism on Egyptian social networking websites.

Egyptian authorities have largely kept the Rafah border crossing with the Gaza Strip closed since former president Mohamed Morsi's removal, citing security concerns in the restive Sinai Peninsula where Islamist militants are active.