An IDF soldier walks next to a truck loaded with donations collected in Israel, before they are delivered over the border to Syria, near the border fence in the Golan Heights, July 5, 2018. Photo: Reuters / Amir Cohen.

An Israeli cabinet minister warned Syria and its backer Russia on Thursday that Israel could attack Damascus’ forces if they try to deploy in a demilitarized border zone while advancing against rebels in the region.

Syrian President Bashar al-Assad launched an offensive last month to regain southern Deraa, and is expected to aim next for rebel-held Queitra, abutting Israel’s Golan Heights.

The fighting has displaced more than 320,000 people, according to the United Nations. Many of them have sought shelter at the Jordanian border or the Golan lines with Israel, generating pressure on both countries to provide relief.

Israeli Prime Minister Benjamin Netanyahu, who meets Russian President Vladimir Putin in Moscow next Wednesday, called twice this week for the preservation of a UN-monitored 1974 Israeli-Syrian armistice barring or limiting military build-ups by either side around the Golan.

“We must verify and do everything to clarify, vis-a-vis the Russians, the Assad government, that we will not accept any armed presence by the Assad regime in the areas which are meant to be demilitarized,” Gilad Erdan, a minister in Netanyahu’s security cabinet, told the Israeli news site Ynet on Thursday.

Asked if Israel was prepared to take preventive action against the Syrian military, Erdan said: “Unequivocally, yes.”

He cited, as precedents, Israeli air strikes carried out in recent months against Syrian facilities deemed to have been used in attacks on Israel or by Assad’s Iranian reinforcements.

“Here, too, if there is a violation, and certainly in the southern Syrian region which is close to the citizens of the State of Israel, and a bringing of weaponry that should not be there, Israel will take action,” Erdan said.

A March report on the activities of the UN Disengagement and Observer Force (UNDOF) on the Golan said Syria’s military maintained positions which violated the 1974 accord, as did Israel’s deployment of 155 mm artillery, Iron Dome anti-rocket systems and related equipment.

Israel on Sunday sent more artillery and tanks to the Golan in what it said was a precaution in light of the Deraa fighting.

The Netanyahu government refuses to provide asylum for refugees from Syria, an enemy country. But Israel‘s military and civilians have stepped up humanitarian relief work on the Golan.

With hundreds of new refugees from Deraa turning up on the Golan daily, foreign volunteers bagged clothing, toys and baby goods that had been donated by Israelis and loaded them onto a truck for transfer and distribution across the boundary fence.

“It’s really quite tremendous,” said Teri Shields, a project director for the Friend Ships Unlimited humanitarian group, which runs a refugee clinic in coordination with Israel.

Israel captured much of the Golan from Syria in the 1967 Six-Day War and later annexed it.

Jordan has been brokering truce talks between Syrian rebels and Russia. Negotiations broke down mid-week but Amman said on Thursday it had persuaded the sides to meet again.