The Israeli air force has struck the base of a Palestinian group in Lebanon, officials said, hours after a different organisation said it had fired four rockets at Israel from Lebanon.
Friday's early morning raid in Naameh, which the Lebanese army said caused no casualties or damage, nonetheless drew condemnation from the Lebanese government as a violation of its sovereignty after it had vowed to hunt down the perpetrators of Thursday's rocket fire.
Israeli aircraft "targeted a terror site located between Beirut and Sidon in response to a barrage of four rockets launched at northern Israel yesterday [Thursday]," the Israeli military said.
"The pilots reported direct hits to the target."
Lebanese President Michel Sleiman, who had condemned Thursday's rocket fire, also denounced the Israeli retaliation, adding that he had asked Foreign Minister Adnan Mansour to lodge a complaint with the UN Security Council.
"Border violations are a matter settled by the UNIFIL panel of inquiry and not by aggression and violation of Lebanese sovereignty as Israel did in Naameh," his office said.
'We will hurt them'
Palestinian and Lebanese officials said the target was a position of the Popular Front for the Liberation of Palestine - General Command (PFLP-GC), an armed secular group that said it had nothing to do with Thursday's rocket fire.
"Around 4am (01:00 GMT), the Israeli air force fired a missile on the Naameh valley without causing any casualties or damage," PFLP-GC spokesman Ramez Mustapha said.
Thursday's salvo of four rockets, which caused damage but no casualties, was claimed by the Abdullah Azzam Brigades, an al-Qaeda-linked group that claimed similar rocket fire on Israel in 2009 and 2011.
Israeli army spokesman Brigadier General Yoav Mordechai said on Thursday that the rockets were "launched by the global jihad terror organisation", an apparent reference to al-Qaeda.
"Israel will not tolerate terrorist aggression originating from Lebanese territory," military spokesman Lieutenant Colonel Peter Lerner said in a statement announcing Friday's air strike.
Commenting on the rocket attacks, Israeli Prime Minister Benjamin Netanyahu said in a statement that "anyone who tries to attack us should know that we will hurt them".
Thursday's rocket fire was the first such incident since May. The rockets were fired from Rashidiyah, a Palestinian refugee camp near the southern city of Tyre in Lebanon.
Israel and Lebanon are technically at war. Israel briefly invaded Lebanon during an inconclusive 2006 conflict with armed group Hezbollah.