Israeli and Lebanese troops have clashed at their shared border, leaving three Lebanese soldiers, one senior Israeli officer and a Lebanese journalist dead.
It is understood that Hezbollah was not part of what was the most serious violence along the frontier since the 2006 war.
The Lebanese and Israeli armies gave different descriptions of the events leading up to the skirmish, while the UN peacekeeping force stationed in southern Lebanon said it had yet to ascertain the circumstances leading to the bloodshed.
The Lebanese army said an Israeli patrol had crossed the technical line of the border even though UN peacekeepers in the area told it to stop.
A spokesman said the clashes erupted after Israeli soldiers attempted to uproot a tree on the Lebanese side of the fenced border.
'The Israelis began to fire and we responded,' he said.
'The Israelis fired four shells (from a tank) that fell near a Lebanese army position on the outskirts of the village of Adaysseh and the Lebanese army fired back,' a security official in the area told AFP, adding that two houses were damaged by the rockets.
An Israeli military source also confirmed that clashes had erupted, saying there was an exchange of fire between Israeli troops and Lebanese forces near kibbutz Misgav Am, which lies just across the border from Adaysseh.
An Israeli army statement said IDF forces were carrying out work inside Israeli territory between the security fence and the international border when they were fired upon.
Earlier reports on Israel public radio said two rockets had been fired across the border to Israel, but Israeli police later denied any projectiles had landed.
The UN force stationed in southern Lebanon has urged 'maximum restraint' following the clashes along the so-called blue line, a UN-drawn border separating Lebanon from Israel.
'Our immediate priority at this time is to restore calm in the area,' said Neeraj Singh, spokesman for the UN Interim Force in Lebanon (UNIFIL).
Lebanese President Michel Sleiman and Prime Minister Saad Hariri have condemned the Israeli attack.
Israel said it holds the Lebanese government responsible for the clash.
Israel's Foreign Ministry said: 'Israel views the Lebanese government as responsible for this serious incident and is warning of the ramification if the violations continue.'
