(CNN) -- An armed group detained 43 U.N. peacekeepers in Syria near the country's only border crossing with the Israeli-occupied Golan Heights early Thursday, a day after militants took the crossing from the Syrian regime, the United Nations said. Those holding the peacekeepers are members of the al Qaeda-linked al-Nusra Front, one of the groups fighting the regime of Syrian President Bashar al-Assad, an Israeli military official told CNN on condition of anonymity. "The United Nations is making every effort to secure the release of the detained peacekeepers, and to restore the full freedom of movement of the force throughout its area of operation," the U.N. said in a news release.

In June 2013, rebels and Syrian forces battled for control of
Quneitra.