Hostilities escalated dramatically across the Israel-Gaza border on Friday evening, after an Israeli air strike killed two terrorists in a car in Gaza City. One of the men killed, Zuhair al-Qaissi, military sources said, oversaw the infiltration of terrorists from the Sinai into Israel north of Eilat last August in which eight Israelis were killed, and he was planning a similar infiltration attack.

Fourteen rockets were fired into Israel on Friday evening, causing no injuries or damage, amid threats of revenge from Gaza. Two more Palestinians were reported killed in subsequent Israeli air strikes. The IDF said the two men killed were about to launch further Kassam rockets into Israel.

Israel’s Homefront Command placed communities adjacent to Gaza on alert. Residents were told to stay close to protected areas for fear of further fire, and festive Purim events planned for the weekend were cancelled.

Israeli military sources said Hamas was not directly involved in the rocket attacks on Friday evening, and that the key question regarding the days ahead was whether it would join the Popular Resistance Committees (PRC) terror group in firing at Israel — a development which would raise tensions still further.

The Israeli strike on Gaza City targeted a vehicle carrying al-Qaissi, the secretary-general of the PRC, and Ahmad al-Khanini, a senior PRC member freed in the Shalit prisoner swap. Ynet News reported a third Palestinian passenger was injured in the air strike.

The car blew up in the neighborhood of Tel al-Hawa, and a video showing the burning wreckage was published on YouTube.

The Salah ad-Din Brigades — the military arm of the PRC — called on its members to retaliate with full force for the strike that killed its leader.

“Blood and sacrifices are the only way to liberate al-Aqsa and Palestine. The Zionist enemy destroyed Zuhair al-Qaissi and opened the doors of vengeance and hell. Our response will be of equal value to this barbaric crime,” a spokesperson said.

The Israeli military said al-Qaissi was plotting an infiltration attack into Israel similar to one his group carried out in August that killed eight people. The IDF warned Gaza’s Hamas rulers against any retaliation for the strike.

Senior Hamas official Ismail Radwan said that the Palestinian people have the right to defend themselves, and that assassinating a prisoner released in the Gilad Shalit swap violates the terms of the deal.

Palestinian witnesses said Israeli drones were seen hovering above just moments before a vehicle exploded into flames, just outside of Gaza City.

The strike came after two mortars were fired from Gaza at southern Israel earlier on Friday. No one was injured and the projectiles landed in an open space near Eshkol.

Gaza-based terror groups have fired some 60 rockets and mortars at Israel in 2012 — and more than 650 in 2011 — according to a tally maintained by The Israel Project.

The Israeli-Gaza border has seen intermittent rocket fire before and since Operation Cast Lead, an IDF ground incursion against Hamas in Gaza in the winter of 2008.

Hamas has controlled Gaza since 2007.