LONDON (Reuters) -- Israeli forces attacked a target on the Syrian-Lebanese border overnight, a Western diplomat and a security source said on Wednesday, at a time of growing concern in Israel over the fate of Syrian chemical and conventional weapons.
The sources, who declined to be named because of the sensitivity of the issue, had no further information about what might have been hit or where precisely the attack happened.
Earlier, the Lebanese army reported a heavy presence of Israeli jets over its territory throughout the night.
"There was definitely a hit in the border area," the source said.
An activist in Syria who works with a network of opposition groups around the country said that she had heard of a strike in southern Syria from her colleagues but could not confirm.
Israel's vice premier Silvan Shalom said on Sunday that any sign that Syria's grip on its chemical weapons was slipping, as President Bashar Assad fights rebels trying to overthrow him, could trigger Israeli intervention.
Israeli sources said Tuesday that Syria's advanced conventional weapons would represent as much of a threat to Israel as its chemical arms should they fall into the hands of Syrian rebel forces or Hezbollah guerrillas based in Lebanon.
Israel has sent its national security adviser, Yaakov Amidror, to Russia and its military intelligence chief Major-General Aviv Kochavi to the United States for consultations, Israeli media said.
In Jerusalem, the Israeli military declined any comment.
"We do not comment on reports of this kind," an Israeli army spokeswoman said.
Vice Premier Silvan Shalom, on Israel Radio, was asked if there was unusual activity on the northern front.
"The entire world has said more than once that it takes developments in Syria very seriously, developments which can be in negative directions. And therefore the world, led by President Obama who has said this more than once, is taking all possibilities into account and of course any development which is a development in a negative direction would be something that needs stopping and prevention."