The UN warned on Monday that Israeli military activity along the Golan Heights buffer zone in Syria "would constitute a violation" of a 1974 pact on disengagement between Israel and Syria.
Told of the Israeli plans, UN peacekeepers "informed the Israeli counterparts that these actions would constitute a violation of the 1974 disengagement agreement, that there should be no military forces or activities in the area of separation," UN spokesman Stephane Dujarric told a news conference.
Stating that the UN Disengagement Observer Force (UNDOF) has seen "unidentified armed individuals that have been manning checkpoints in the area of operations," Dujarric said UNDOF can also confirm that the Israeli army personnel "entered the area of separation and have been moving within that area where they remain in at least three locations throughout the area of separation."
Dujarric reported that the Israeli army said it "would enter that area as 'a temporary defensive measure' to prevent it from being occupied by non-state armed groups. The Israelis also told our UNDOF colleagues that it reserved the right to take any action against any threat against the state of Israel," he said.
"The peacekeepers in UNDOF informed the Israeli counterparts that these actions would constitute a violation" of the 1974 agreement, he said, adding: "Israel and Syria must continue to uphold the terms of that 1974 agreement and preserve stability."
In a letter addressed to the presidency of the UN Security Council, Israeli Ambassador Danny Danon claimed that the Israeli army "assisted" UNDOF in repelling an attack from armed groups entering the area of separation.
"In response to this evolving security threat and the danger posed by it to Israel-particularly to the residents of the Golan Heights-Israel has taken limited and temporary measures to counter any further threat to its citizens," he said, adding that Israeli army has been "temporarily" deployed to several points in the area of separation as part of its security measures.
Danon added that the Israeli army "will continue to act as necessary in order to protect the State of Israel and its citizens."
"It is important to emphasize, however, that Israel is not intervening in the ongoing conflict between Syrian armed groups; our actions are solely focused on safeguarding our security," he said, calling Israeli military actions "limited and temporary."
On Sunday, the Israeli army imposed "closed military zones" in Syria's occupied Golan Heights following the sudden fall of the Assad regime.
In response to military concerns about the potential infiltration of armed groups, the Israeli army deployed additional forces along the buffer zone separating Syria and the occupied Golan Heights.
Bashar al-Assad, Syria's leader for nearly 25 years, fled to Russia after anti-regime groups took control of Damascus early Sunday, signaling the collapse of the Baath Party regime, which had been in power in Syria since 1963.
This followed the seizure of Aleppo, a major northern Syrian city, by anti-regime groups nearly a week earlier.
Signed on May 31, 1974, the agreement stipulates Israel's withdrawal from all of the areas of Mount Hermon it had occupied during the 1973 Arab-Israeli War as well as an area of about 25 square kilometers (9.6 square miles) that included Quneitra and other locations.
The agreement defines the current border between Israel and Syria along with the accompanying military arrangements, creating two separation lines-Israeli (blue) and Syrian (red)-with a buffer zone between them.
The agreement is monitored by the UNDOF, as it is tasked with maintaining the cease-fire between Israel and Syria following the 1973 war.
Since 1974, UNDOF has patrolled the buffer zone between the Israeli- and Syrian-controlled zones.
Israel occupied most of the Golan Heights during the 1967 Middle East war and later annexed the territory in a move never recognized by the international community.