Rockets were fired from Syria late Saturday after Israel began calling up police and army reservists following attacks that killed three people, including an Italian tourist, and earlier rocket fire from Lebanon.
Despite appeals for restraint, violence has surged since Israeli police forcibly entered the Al-Aqsa mosque on Wednesday after they said Palestinians barricaded themselves inside.
Israel bombarded both Gaza and Lebanon in response to rocket fire by Palestinian militants.
Late Saturday three rockets were fired from Syria, the Israeli army said.
"One of the rockets crossed into Israeli territory and landed in open areas in the southern Golan Heights" which are occupied by Israel, the army said.
The unrest comes as the Muslim holy fasting month of Ramadan, Jewish Passover, and Christian Easter coincide.
It is the latest in escalating Israeli-Palestinian violence since the new government of veteran Prime Minister Benjamin Netanyahu took power in December, a coalition with extreme right and ultra-Orthodox Jewish parties.
The Italian was killed and seven other tourists wounded when an Israeli Arab ploughed a car into pedestrians on the Tel Aviv seafront on Friday evening.
Italian Prime Minister Giorgia Meloni named the dead man as Alessandro Parini, 36.
The car flipped over before the driver was shot dead, police and emergency services said. Police identified the driver as a 45-year-old from the Arab town of Kfar Kassem in central Israel.
"The terrorist was neutralised," a spokesman told AFP.
Three of the injured were still in hospital on Saturday as passers-by left flowers and lit candles at the scene.
Italian President Sergio Mattarella condemned in a press release a "despicable terrorist act". The Rome public prosecutor's office has opened an investigation.
Palestinian Islamist movement Hamas, which rules the Gaza Strip, called the attack a "natural and legitimate response" to Israel's "aggression" in the Al-Aqsa mosque.
Earlier Friday, two British-Israeli sisters aged 16 and 20 were killed and their mother seriously wounded when their car was fired on in the Jordan Valley in the Israeli-occupied West Bank.
After the Tel Aviv attack, Netanyahu instructed the police to "mobilise all reserve border police units" and directed the army to "mobilise additional forces", his office said.
Police said four reserve battalions of border police would be deployed in city centres from Sunday.
The defence ministry confirmed late Saturday it had mobilised soldiers to support the police, and that it would tighten entry restrictions into Israel for Palestinians from the West Bank and Gaza, in particular workers.
Earlier, an Israeli military post came under fire in a drive-by shooting in the northern West Bank town of Yabad overnight Friday-Saturday, the army said.
Soldiers returned fire and hit one person in the vehicle, the army said.
Cross-Border Strikes
Friday's attacks came after Israel launched air strikes and an artillery bombardment before dawn in response to rocket fire from the Gaza Strip and Lebanon.
It was the heaviest rocket fire from Lebanon since Israel fought a 34-day war with Iran-backed group Hezbollah in 2006, and the first time Israel has confirmed an attack on Lebanese territory since April 2022.
Israel "struck targets, including terror infrastructures, belonging to the Hamas terrorist organisation in southern Lebanon", the army said.
In Gaza, Israel's military said it had hit two tunnels and "two weapon manufacturing sites" in response to the "security violations of Hamas".
It said air defences had intercepted 25 rockets from Lebanon on Thursday, while five had hit Israeli territory.
Israel "will not allow the Hamas terrorist organisation to operate from within Lebanon", it said.
The United Nations Interim Force in Lebanon (UNIFIL), which patrols the area along the border, urged restraint, noting: "Both sides have said they do not want a war."
On Friday evening, the army said it had shot down a drone that entered Israel's airspace from Lebanon.
Mosque Raid
On Wednesday, Israeli riot police forcibly entered the prayer hall of Al-Aqsa mosque in a pre-dawn raid, aiming to dislodge "law-breaking youths and masked agitators" they said had barricaded themselves inside.
Ramadan coincided with the Jewish Passover holiday this year, raising tensions with the tens of thousands of Palestinians who pray at Al-Aqsa during the Muslim fasting month.
The Palestinians fear Netanyahu's hard-right government may change longstanding rules that allow Jews to visit but not pray in the mosque compound, despite his repeated denials.
The upsurge of violence drew condemnation from the European Union and the United States.
A Qatari official said Doha was mediating between Israel and the Palestinians.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)