An Israeli soldier drives an armored personal carrier during a military exercise in the Israeli controlled Golan Heights, near the border with Syria, Tuesday, May 7, 2013. AP Photo/Ariel Schalit An Israeli soldier of the Golani brigade covers himself in a prayer shawl as others gather for the morning prayer before a military exercise in the Israeli controlled Golan Heights, near the border with Syria, Tuesday, May 7, 2013. Israeli soldiers of the Golani brigade, few covered in a prayer shawls gather for the morning prayer before a military exercise in the Israeli controlled Golan Heights, near the border with Syria, Tuesday, May 7, 2013. Israeli soldiers of the Golani brigade, few covered in prayer shawls, gather for the morning prayer before a military exercise in the Israeli controlled Golan Heights, near the border with Syria, Tuesday, May 7, 2013. Israeli soldiers of the Golani brigade gather in a tent, as the sun rises, before a military exercise in the Israeli controlled Golan Heights, near the border with Syria, Tuesday, May 7, 2013. BEIRUT (AP) - Rebels fighting to topple Syrian President Bashar Assad detained four U.N. peacekeepers on Tuesday in area that separates Syria and Israel, raising tension between the two countries just days after the Jewish state launched back-to-back airstrikes near Damascus. The abduction was the second such incident in the area in two months. The incident exposed the vulnerability of the U.N. peacekeeping mission during the Syrian civil war, now in its third year. It also sent a worrisome signal to Syria's neighbors - including Israel - about the ensuing lawlessness along their shared frontiers. Rebels with the Yarmouk Martyrs Brigades are holding the peacekeepers, a spokesman for the group told The Associated Press in a phone interview. The Yarmouk Brigades were behind the abduction in March of 21 Filipino U.N. peacekeepers released unharmed after four days of tough negotiations. The spokesman talked with the AP on condition of anonymity because he was outside of Syria serving as a mediator on peaceful matters concerning the group. In New York, Kieran Dwyer, spokesman for the U.N. peacekeeping department, confirmed the abduction and said the four peacekeepers, all from the Philippines, were taken on Tuesday by an unidentified armed group near the town of Jamla in southern Syria. "Efforts are underway to secure their release now," Dwyer said. In a statement posted on the Yarmouk Brigades' Facebook page, the group said the peacekeepers were not hostages, but were being held for their own safety. The statement did not specify where the peacekeepers were being held, nor did it specify conditions for their release. The rebel unit said it suspects the U.N. peacekeepers are shielding Assad's troops, who the rebels said killed civilians during an army sweep of Wadi Raqat in the south. The U.N. monitoring mission was set up in 1974, seven years after Israel captured the Golan Heights and a year after it managed to push back Syrian troops trying to recapture its territory in another regional war. For nearly four decades, the U.N. monitors have helped enforce a stable truce between Israel and Syria. But in recent months, Syrian mortar shells overshooting their target have repeatedly hit the Israeli-controlled Golan. Israel's recent airstrikes inside Syria raised the possibility of a wider regional conflict as a result of the civil war in which more than 70,000 Syrians have been killed. Israeli officials have said the airstrikes were meant to prevent advanced Iranian weapons from reaching Lebanon's Hezbollah militia, an ally of Syria and foe of Israel. Syria has hinted at possible retribution against Israel for the raid, although official government statements have been relatively mild. On Tuesday, however, a Syria-based Palestinian militant group said it got a go-ahead from the Assad regime to set up missiles to attack Israel in the wake of the airstrikes. "Syria has given the green light to set up missile batteries to directly attack Israeli targets," Anwar Raja, the spokesman for the Popular Front for the Liberation of Palestine-General Command, told the AP. He said authorities also told his group that it could carry out attacks independently without consulting Syrian authorities. "Practically, the Syrian stand has always been supportive of the Palestinian resistance and Syria provides the Palestinian resistance with all capabilities including all kinds of weapons," Raja said. When the revolt against Assad's rule began in March 2011, the Palestinian community in Syria largely stayed on the sidelines. But as the uprising shifted into a civil war, many Palestinians backed the rebels, while some groups have been fighting on the government side. Those include the Popular Front, a small Damascus-based Palestinian militant faction that the U.S has designated a terrorist organization. While the group earned notoriety for its past attacks on Israel, it has been eclipsed in the past 20 years by the other Islamic militant groups, such as Hamas and Islamic Jihad. The Assad regime's decision to allow a minor Syria-based Palestinian group to prepare for attacks is largely seen as a face-saving gesture unlikely to escalate Syria's confrontation with Israel. Iran, a close ally of Damascus, has condemned the Israeli attacks and warned of possible retaliation, which it said should come from Israel's Arab neighbors, not Tehran. Iran's Foreign Minister Ali Akbar Salehi was in Damascus on Tuesday, meeting with Assad and other Syrian officials, according to Syrian state TV. There were no details on issues discussed during the talks. Earlier Tuesday, Salehi told reporters in Amman, Jordan, that Arab nations "must stand by their brethren in Damascus." Iran is deeply concerned with the fate of the Assad regime, which has allowed Syrian territory to serve as a conduit for Iranian weapons and other support to reach their proxy, Hezbollah. Tehran has supplied cash and weapons to help the Syrian government in its efforts to crush the anti-Assad revolt. Salehi warned of the possible repercussions if the government in Damascus was to fall. "The fallout from a vacuum in Syria will have adverse effects on its neighbors and the whole region," he said. There will be serious repercussions from a vacuum. It will be grave and nobody can predict the results. AP writers Bassem Mroue in Beirut, Edith M. Lederer at the United Nations, Jamal Halaby in Amman, Jordan, and Albert Aji in Damascus, Syria, contributed to this report.