Activists are trying to mobilize Palestinians for a new march on Israel’s borders, seeking to replicate the massive demonstrations last month that converged on Israel from Syria, Lebanon, Gaza and the West Bank.

The new effort is planned for Sunday and is largely being organized through social media, which activists have enlisted to coordinate efforts among Palestinians scattered across multiple frontiers. Fourteen people were killed and scores were wounded May 15 when Israeli troops opened fire on marchers as they approached borders, surging across the frontier in the Israeli-held Golan Heights.

Many Palestinians see the coordinated marches as offering a potent demonstration of the effectiveness of unarmed protests, raising hopes that popular action could bring change in the Arab-Israeli conflict, as it is bringing change elsewhere in the upheavals sweeping the Middle East.

The mobilization of the Palestinian diaspora has clearly boosted a sense of unity. But it has also pushed the conflict with Israel back to its intractable core, highlighting calls for the return of Palestinian refugees to their former homes — a demand Israel views as an existential threat.

“For the first time ever, the Palestinians have switched from commemorating their displacement with statements, festivals and speeches, to actual attempts to return to their homes,” said a call to protest issued by the Preparatory Committee for the Marches of Return to Palestine. “The May 15 marches were not an isolated incident, but a declaration of the foundation of a new stage of struggle.”

In the demonstrations planned for this weekend, marchers have been urged to carry Palestinian flags, signs with the names of their former communities in what is now Israel, and keys symbolizing the homes from which they fled or were expelled in the war that accompanied the creation of Israel in 1948.

The marches are timed to commemorate the anniversary of the outbreak of the 1967 Middle East war, in which Israel captured the West Bank, the Gaza Strip and the Golan Heights.

Under pressure from the Lebanese government, which declared the border area with Israel a closed military zone, organizers in Lebanon said Friday that they were canceling plans to march to the frontier and would hold strikes in Palestinian refugee camps instead. But protests in other areas were expected to go ahead as planned.

Although organizers are calling for peaceful marches, copying the tactics of demonstrators in other Arab countries, last month’s protests ended in rock-throwing clashes with Israeli troops and a breach of the border fence in the Golan Heights. The Israeli army is planning to beef up its presence along the borders and at expected flash points in the West Bank and Gaza Strip on Sunday, equipping troops with non-lethal riot control gear such as tear gas and rubber bullets — a reaction to last month’s confrontations, in which soldiers resorted to live ammunition.

Accusing Iran, Syria and the militant groups Hamas and Hezbollah of orchestrating the protests, Israeli Prime Minister Binyamin Netanyahu said Thursday that he had instructed Israeli forces “to act with restraint but determination to protect our borders.”

Palestinian activists in the West Bank say the motivation for protest has been fueled by the impasse in peace efforts and widespread public disillusionment, which they say was deepened by Netanyahu’s hawkish statements during his recent visit to Washington.

“The political parties cannot do anything — they only talk,” said Hazem Abu Helal, an activist in Ramallah, referring to the established Palestinian factions. “The youth work on the ground.”

Abu Helal said that local youth organizers had met with Arab counterparts in recent months at conferences abroad and that a loose coalition of local groups was organizing parallel protests inside and outside the Palestinian territories, using social media to spread the message.

In the Gaza Strip, for example, a group calling itself the Committee to Resist the Buffer Zones has joined other factions in calling for a march Sunday to a zone along the border with Israel where the Israeli army has used gunfire to keep Palestinians away, declaring it off-limits. The army says the ban has been imposed to prevent attacks on its patrols.

The March 15 Youth Coalition, named after a day of protests it organized in the West Bank and Gaza Strip that helped spur the reconciliation accord between the rival Palestinian factions Fatah and Hamas, declared Sunday a “day of popular rage” against the Israeli occupation and in support of efforts to obtain recognition of Palestinian statehood at the United Nations in September.

In Syria, there are plans to bring hundreds of buses carrying Palestinians to the border with the Golan Heights, in coordination with the Syrian authorities. And at the Qalandia checkpoint between Ramallah and Jerusalem in the West Bank, a mass prayer is planned.

Z, a West Bank activist who declined to be identified further because his place of work bars political activity, said the coordinated unarmed protests were confronting Israel with a novel challenge.

“These tactics are putting the Israelis in a corner,” he said, “showing the real occupation on the ground without giving the Israelis a chance to say that the Palestinians are violent and terrorists.”