Hezbollah vows to attack al-Nusra Front on Syria frontier
Hezbollah leader Hassan Nasrallah says his Lebanon-based Shia group will attack Sunni militants from al-Nusra Front along the border with Syria.
Mr Nasrallah said al-Nusra units based in the Qalamoun Mountains would be targeted, but did not specify when.
He said the group, which has launched a series of attacks on Hezbollah fighters in Syria, posed an unacceptable threat.
Hezbollah, an ally of Syrian President Bashar al-Assad, has sent hundreds of fighters to join the Syrian civil war.
'Time will tell'
In a televised address on Tuesday, Mr Nasrallah said attacks by militants from the al-Qaeda affiliated al-Nusra Front posed an unacceptable threat to Lebanon's security and required "radical treatment".
"The [Lebanese] state is not able to address this issue... so we will proceed with the necessary treatment and assume the responsibility and consequences," he added.
He declined to say when the operation would begin adding: "Even when we start, we will not issue a statement. When we begin, the operation will speak for itself."
Most of the border region was recaptured from rebel forces last year after a major assault by Syrian government troops, backed by Hezbollah fighters.
However, jihadists entrenched there have continued to launch attacks, with clashes reported as recently as Tuesday.
Lebanese officials say several hostages, including soldiers and police officers, are still being held after being seized in the Lebanese border town of Arsal last year.
Fighting from Syria frequently spills over into neighbouring Lebanon, with cross-border clashes and bombings.
The conflict in Syria has also exacerbated existing tensions in Lebanon - which suffered its own civil war between 1975 and 1990 - and made Hezbollah and areas which support it targets for Sunni militant bomb attacks.