The head of Israel's armed forces warned Syrian President Bashar al-Assad on Tuesday of "consequences" if fire continues from Syrian territory against Israeli troops in the occupied Golan Heights.
"If he disturbs the Golan Heights, he will have to bear the consequences," Lieutenant General Benny Gantz said in an address at Haifa University and broadcast on Israeli television.
"We cannot and shall not allow the Golan Heights to become a comfort zone for Assad," he said.
He spoke hours after Israeli troops and Syrian forces exchanged fire across the sensitive ceasefire line on the Golan Heights, but the Jewish state denied Syrian claims one of its vehicles had been destroyed.
The Syrian army "fired on an Israeli patrol, which we confirmed six hours ago, but did not destroy a vehicle or kill anyone," Israeli military spokesman Avichai Adraee wrote on Twitter.
"In response, Israel Defence Forces returned precise fire at the source of the gunfire. They reported a direct hit," an army statement added.
Syria claimed to have destroyed an Israeli military vehicle it said had crossed the ceasefire line during the incident.
"The vehicle passed the ceasefire line and was moving towards the village of Bir-Ajam situated in the liberated Syrian zone" of the Golan, it said, adding that the operation was aimed at "lifting the morale" of rebel forces in the region.
Gantz said that the vehicle never entered Syrian-controlled territory and suggested that Syria was fabricating a story with an obsolete Israeli vehicle left behind in Lebanon during Israel's 2006 war there against Syrian ally Hezbollah.
"It's a totally absurd story about an old 2002 model jeep," he said.
On Monday too, the army reported that small-arms fire from Syria hit the Israeli-occupied Golan overnight, causing no harm or damage. The army filed a complaint with the UN force.
The strategic plateau has been tense since the beginning of the conflict in Syria more than two years ago.
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However, there have been only minor flare-ups in the area to date, with Syrian shells crashing in the occupied Golan and Israel firing in retaliation.
In recent weeks there were four incidents of fire coming from Syria and straying across the ceasefire line.
Last week projectiles from Syria hit Mount Hermon, causing the popular site on the Golan to close down to visitors.
Defence Minister Moshe Yaalon said on Tuesday that Israel did not want to get sucked into Syria's war, but that fire at Israeli targets from across the border would not be tolerated.
"Our policy is clear: we will not intervene in the Syrian civil war, but concerning the situation in the Golan Heights, we will not permit gunfire against our territory," he said in a statement.
Maariv daily quoted an Israeli commander in the north of the country as warning that "if one of these shells causes an (Israeli) casualty, the response will be different."
The US State Department warned on Monday that the occupation of villages along the Lebanese-Syrian border by Hezbollah "inflamed regional sectarian tensions."
Israel launched air raids inside Syria this month targeting what sources said were arms destined for its arch-foe Hezbollah, whose members have joined the fight against rebels alongside the Syrian military.
The strikes ramped up regional tension, with Syria threatening to hit back.
In a separate incident on Tuesday, Israel's army also said an injured Syrian was taken overnight to a hospital in northern Israel after crossing the ceasefire line.
A number of Syrians wounded from the fighting next door have been treated in Israeli hospitals over the past few months, before being repatriated.
Israel, which is technically at war with Syria, seized 1,200 square kilometres (460 square miles) of the Golan from its Arab neighbour in the 1967 Six-Day War.
It later annexed the territory, in a move never recognised by the international community.