The UN special envoy for Syria called Tuesday on Israel to halt its military movements and bombardments in Syria, after a war monitor reported 300 air strikes since the fall of regime leader Bashar al-Assad.
Assad fled Syria as the Syrian opposition forces swept into the capital Damascus, ending five decades of brutal rule by his clan on Sunday.
Abu Mohammed al-Jolani, the HTS leader who headed the offensive that forced Assad out, has begun talks on a transfer of power and vowed to pursue former senior officials responsible for torture and war crimes.
The fall of Assad, who maintained a complex web of prisons and detention centres to keep Syrians from straying from the Baath party line, sparked celebrations around the country and in the diaspora all over the world.
Syria's civil war killed 500,000 people and forced half the country to flee their homes, millions of them finding refuge abroad.
The country now faces profound uncertainty after the collapse of a government that had run every aspect of daily life in the image of Assad and his father, from whom the ousted president inherited power.
Israel has conducted many strikes on Syria since the civil war began in 2011 with Assad's crackdown on a democracy movement.
The Syrian Observatory for Human Rights said it had recorded more than 300 Israeli strikes since Assad was deposed.
Geir Pedersen, the UN special envoy for Syria, on Tuesday called on Israel to stop.
"We are continuing to see Israeli movements and bombardments into Syrian territory. This needs to stop. This is extremely important," he told reporters in Geneva.
AFP journalists in the capital Damascus heard loud explosions on Tuesday but could not independently verify the source or scope of the attacks.
Israel, which borders Syria, sent troops into a buffer zone east of the Israeli-annexed Golan Heights after Assad's fall, in what Foreign Minister Gideon Saar described as a "limited and temporary step" for "security reasons".
Israeli Prime Minister Benjamin Netanyahu said Monday that the Golan Heights, occupied by Israel for almost 60 years, would perpetually remain part of Israel.
Israel backer the United States said the incursion must be "temporary", after the United Nations said Israel was violating a 1974 deal.
The Israeli military on Tuesday denied reports that its tanks were advancing towards Damascus, insisting that its forces were stationed within the buffer zone.
Assad spent years suppressing rebellion using everything in his means, including air strikes and even chemical weapons, but he was ultimately deposed in a lightning offensive that lasted less than two weeks.
The opposition forces launched their offensive on November 27, the same day a ceasefire took effect in the Israel-Hezbollah war.
The war saw Israel inflict staggering losses on Hezbollah, which had for years fought in support of Assad's government in Syria, long a conduit of weapons for the militant group from Iran.