Palestinians across the war-ravaged Gaza Strip have marked the start of one of Islam's most important holidays, amid little hope the conflict will end any time soon, Sky News reported.

Much of Gaza lies in ruins, with men and children forced to hold the traditional Eid al Adha prayers in the open air, and as food supplies dwindle.

Food and aid were blocked from entering the Palestinian territory for more than two months, but a trickle of supplies has been allowed in over the last few weeks.

The UN said it cannot distribute much of the aid, due to the risk of looters and restrictions on movement.

"This is the worst feast that the Palestinian people have experienced because of the unjust war against the Palestinian people," said Kamel Emran after attending prayers in the southern city of Khan Younis.

"There is no food, no flour, no shelter, no mosques, no homes, no mattresses... The conditions are very, very harsh."

The Islamic holiday begins on the 10th day of the Islamic lunar month of Dhul-Hijja, during the Hajj season in Saudi Arabia.

It is the second year Muslims in Gaza have been unable to travel to the country to perform the traditional pilgrimage.