Lebanon's Hizb Allah said its fighters on Saturday attacked the Israeli position of Roueissat al-Alam in the Shebaa Farms in retaliation for "heavy machine-gun fire" by Israeli forces targeting houses in areas facing the farms.
"The Islamic Resistance (Hizb Allah's military wing) attacked the Israeli position ... with the appropriate weapons, scoring direct hits," the statement said.
In Jerusalem, an Israeli army spokesman said soldiers had fired a number of warning shots in the air when they saw several shepherds attempting to cross the border into Israel.
About half an hour later soldiers saw trajectory missiles fired across the border from Lebanon., the spokesman said.
A total of eight missiles or rockets were fired from Lebanon. No injuries or damage were reported.
"This is a very serious cross-border escalation, especially since we saw a large number of shells being fired last week by Hizb Allah. ... This is their attempt to heat up the border," the army spokesman said on condition of anonymity.
There was no immediate word on casualties from either the Israeli shooting or the Hizb Allah attack.
Periodic clashes occur between
Israel and the Hizb Allah
Hizb Allah and the Israeli army periodically have cross-border clashes in the Israeli-occupied Shebaa Farms, where the borders of Syria, Lebanon and Israel meet.
Lebanon claims the area but the United Nations says it is part of Syria. Earlier this month, the sides had the heaviest clash in months, exchanging barrages of shells and rockets across the Lebanese border. Israeli warplanes destroyed a series of Hizb Allah positions.
"The Islamic Resistance (Hizb Allah's military wing) attacked the Israeli position ... with the appropriate weapons, scoring direct hits"
Hizb Allah statement
The border tension comes a few days before the fifth anniversary of Israel's withdrawal from southern Lebanon.
Hizb Allah led a guerrilla war against Israel's 18-year occupation of South Lebanon.
Hizb Allah is under international pressure to disarm, with a UN resolution demanding militias in Lebanon give up their weapons.
The group has refused, and Lebanese authorities have resisted pressuring Hizb Allah, calling it a resistance movement, not a militia. The Lebanese army has not deployed in the south, allowing Hizb Allah to control security there since the Israeli withdrawal.