Israeli troops entered the UN-patrolled buffer zone that separated Israeli and Syrian forces on the Golan Heights last weekend in a move the United Nations said violated the 1974 armistice agreement.

"The Israelis have crossed the disengagement line in Syria, which threatens a new unjustified escalation in the region," said the leader of the Hayat Tahrir al-Sham group, Abu Mohammed al-Jolani, who is now using his real name Ahmed al-Sharaa.

But he added in a statement on the rebels' Telegram channel that "the general exhaustion in Syria after years of war and conflict does not allow us to enter new conflicts."

Israel occupied most of the Golan Heights from Syria during the 1967 Arab-Israeli war.

It held onto the territory during the 1973 war and in 1981 annexed the area in a move not recognised by the international community.

Since the overthrow of President Bashar al-Assad by HTS-led forces on Sunday, Israel has also carried out hundreds of air strikes on Syrian military assets, more than 600 airstrikes according to a war monitor.

On the other hand, the Israeli military said that it conducted about 480 strikes last Sunday and Monday, on Syrian military assets, targeting everything from chemical weapons stores to air defences.

Israel's Defence Minister Israel Katz ordered the Israeli army to "prepare to remain" throughout the winter in the now occupied buffer zone.

Israel also seized the demilitarised zone on the strategic plateau Jabal Al-Shaikh, just hours after Syrian rebels swept al-Assad from power.