A 15-year-old boy has been killed in the occupied Golan Heights by firing from Syria, Israel says.
Officials say he was with his father in a truck which took a "direct hit".
The father and another contract worker are reported to have been injured. They were was carrying out maintenance work on the border fence,
It is unclear whether Syrian rebels or government forces were behind the incident, but Israel responded with tank shelling into Syria.
The exchange took place in the Tel Hazeka area, near the Quneitra crossing, the Israeli defence ministry said.
It is the first time an Israeli has been killed by firing from Syria in the Golan Heights since the Syrian conflict began in 2011.
Israeli military spokesman, Lt Col Peter Lerner, told AP news agency the firing from Syria was "clearly intentional" but it was unclear whether it was the result of mortar fire, a roadside bomb or shelling.
The Golan Heights, a rocky plateau in south-western Syria, was seized by Israel from Syria in the closing stages of the 1967 Middle East War.
The two countries remain technically in a state of war, and UN observers are deployed to monitor a 70km-long (45-mile) demilitarised zone.
Firing linked to the Syrian conflict occasionally reaches the Israeli side of the border fence - some unintentional, some said to be deliberate.
In March, Israel conducted air strikes against several Syrian military targets after a bombing that injured four of its soldiers in the Golan Heights.
Israel had accused the Syrian army of "aiding and abetting" the attack on a patrol near the ceasefire line.
Syria said one of its soldiers was killed in the Israeli military response.
Some of Israeli's recent air strikes are believed to have prevented the transfer of stockpiles of rockets from the Syrian government to Hezbollah, the Lebanese Shia Islamist movement that supports President Bashar al-Assad.