Two Palestinian militants have been wounded in an Israeli air strike on their base in Lebanon, hours after rockets hit two Israeli border towns.
Israel's air force is equipped with F-16 fighter planes
The Israeli warplanes targeted the base of the pro-Syrian Popular Front for the Liberation of Palestine-General Command in the al-Naima area, south of Beirut.
"This is in response to the firing of projectile rockets last night toward Israeli communities," the army said.
A PFLP-GC spokesman denied his group had carried out the rocket attacks.
"Israel wants to blame us for the rocket attacks to provoke a hostile reaction against us in Lebanon," Anur Raja told the AFP news agency.
"We say to our Lebanese brothers that we were in no way implicated."
Mr Raja said that the missile strike at 0430 (0230 GMT) had blown a hole in a concrete wall.
At least four rockets fired from Lebanese territory hit Israeli towns close to the border on Tuesday evening without causing casualties.
Several people were treated for shock in Kiryat Shmona
Three of the Katyusha rockets hit Kiryat Shmona, directly hitting one house and knocking out electricity.
Three houses in all were damaged and three people were treated for shock but the only injury caused was to a dog, Israel's Haaretz newspaper reported.
Residents were temporarily ordered into shelters and the electricity was out for half an hour.
A fourth rocket hit the town of Shlomi.
Lebanese police said at least seven rockets had been launched from Lebanese territory.
Two were fired from the western sector, 20km (12 miles) south-east of Tyre, and five others from the eastern sector on Adaisa hill, they added.
"The Palestinian groups are responsible for Katyusha rocketing of Kiryat Shmona, but I would not be surprised if Hezbollah had given them the green light," General Udi Adam, commander of forces in Israel's northern region, told Israeli radio.
"We will not permit the firing of Katyushas against our territory becoming the norm," he added.
"We hold the Lebanese government responsible for the operations against Israel from its territory, and our raid must be understood as a warning."
A Hezbollah spokesman told the agency he knew nothing of the attacks while a Palestinian Fatah movement official in Lebanon, Sultan Abu-Aynain, strongly denied any involvement by Palestinians.
The border zone has been tense since Israel left south Lebanon in 2000.