JERUSALEM — Hundreds of demonstrators gathered on both sides of the Israeli-Gazan border on Thursday to mark a year since Israel’s three-week war in Gaza, and to call for an end to the blockade of the area imposed by Israel and Egypt.

About 85 of the several hundred demonstrators inside Gaza were foreigners, part of a group of more than 1,000 who arrived in Cairo in hopes of entering the territory but who were stopped by the Egyptian authorities. After days of negotiation, Egypt permitted a small delegation to cross the normally closed border at the southern Gazan city of Rafah.

On the Israeli side, about 1,000 people rallied in protest as well, most of them Israeli Arabs but some of them Israeli Jews who object to the blockade. They carried banners with pictures of children in destroyed buildings. Through the cellphone of an Arab member of the Israeli Parliament, Talab el-Sana, the Hamas prime minister in Gaza, Ismail Haniya, addressed the Israelis and thanked them.

The Gaza marchers waved Palestinian flags and held banners that called for a lifting of the closure, imposed after Hamas took control of Gaza in 2007. The marchers chanted “Free Palestine!” and “No to the siege!”

A Hamas spokesman in Gaza, Taher al-Nunu, welcomed the foreigners and said at their rally: “We are not alone in Gaza. We have many friends outside Palestine who came to protest the siege and the Israeli occupation.”

One of the visiting demonstrators, Julia Harley, 26, of New Jersey, said she and her fellow marchers “want the American people to understand what is happening here, and to pay attention.”

A year ago, Israel fought for three weeks in Gaza to stop the shooting of thousands of rockets from there into its southern communities, like Sderot. About 1,300 people were killed and 4,000 homes destroyed. Reconstruction material remains barred from entering Gaza. The rockets, however, have essentially been stilled.

In Sderot on Thursday, about 200 children holding Israeli flags attached letters of peace to white balloons and sent them aloft on a hillside toward Gaza. But the wind was unfavorable and the balloons flew in the opposite direction.

Fares Akram contributed reporting from Gaza, and Rina Castelnuovo from Sderot, Israel.