Israel struck Beirut airport and Hizbollah's television station on Thursday and killed 22 civilians in raids on south Lebanon, intensifying its reprisals after Hizbollah captured two Israeli soldiers and killed eight.

Hizbollah retaliated for Israeli "massacres" by firing 60 rockets at Nahariya in northern Israel. The Israeli army said Katyusha rockets had hit the city. A civilian was killed.

The violence was the worst between Israel and Lebanon since 1996 when Israeli troops still occupied part of the south. It coincided with an major Israeli offensive into the Gaza Strip to retrieve a captured soldier and halt Palestinian rocket fire, Reuters information agency reports.

An Israeli helicopter fired a missile at the headquarters of Hizbollah's al-Manar TV in the Beirut suburb of Haret Hreik, wounding six people, witnesses and a security source said.

One of the wounded was an al-Manar employee, the station's director said. The building, in a Shiite neighborhood where Hizbollah leaders also have offices, was slightly damaged.

The strike came two hours after aircraft bombed two runways at Beirut international airport as part of an Israeli assault in Lebanon in retaliation for Wednesday's Hizbollah attacks in which two Israeli soldiers were captured and eight killed.

Lebanese security sources said Israeli aircraft fired at least six rockets at runways of Rafik al-Hariri International Airport and a nearby road, forcing flights to divert.

The airport terminal and planes were not hit. It was not immediately clear how badly the raid had damaged the runways.

An Israeli army spokesman confirmed the airport attack.

It followed waves of dawn air strikes against targets in southern villages which killed at least?36 civilians and wounded dozens, security sources said. Ten members of one family were killed in Dweir village and seven family members died in Baflay.

"In response to the massacres of civilians in the south and assaults on (Lebanese) infrastructure, the Islamic resistance bombarded ... the settlement of Nahariya in northern occupied Palestine with 60 rockets," a Hizbollah statement said.

Israel had promised a "very painful" response to Hizbollah's cross-border attack on Wednesday, for which Prime Minister Ehud Olmert's cabinet said the Lebanese government was responsible.

Before the attack on Nahariya, Hizbollah said it fired shells and rockets at an airforce command center in northern Israel and attacked six army border posts early on Thursday.

Dozens of Israeli air strikes hit at least 12 bridges and many suspected Hizbollah posts on Wednesday, killing two Lebanese civilians and a Hizbollah fighter as well as disrupting landline telephone links between Beirut and the south.

The Israeli assault will increase domestic pressure on Hizbollah, which has refused to disarm in line with a 2004 U.N. resolution, and add to international calls on the Lebanese government, led by an anti-Syrian coalition, to act.

Israel must now cope with Hizbollah's hardened Shiite Muslim fighters, but signaled there would be no let-up in its Gaza offensive, mounting an air strike that destroyed the office of Palestinian Foreign Minister Mahmoud al-Zahar.

No one was hurt in the night raid on the Foreign Ministry building in Gaza City, Palestinian security officials said.

A separate air strike, near Deir el-Balah in the central Gaza Strip, killed an Islamic Jihad militant and wounded another gunman, the officials said.

Israel killed at least 24 Palestinians in the Gaza Strip on Wednesday, including nine members of one family in an air strike on a house where the army said Hamas commanders were meeting.

Zahar is a leader of Hamas, an Islamist militant group that won Palestinian elections in January.

Hizbollah leader Sayyed Hassan Nasrallah said the two soldiers had been seized to force Israel to release prisoners. Israel insisted it would discuss no such swap to win the return of the soldiers held in Lebanon or Gaza.

"You don't negotiate with terror organizations," Gideon Meir, senior Israeli Foreign Ministry official, told Reuters.

In 2004, Hizbollah traded a kidnapped Israeli businessman and the bodies of three soldiers for more than 420 Arab prisoners in a deal with Israel brokered by Germany.

Lebanese Prime Minister Fouad Siniora said his government had not known of the Hizbollah attack and did not endorse it.

The White House condemned the Hizbollah attack and blamed Syria and Iran, which both back the Shiite group. Syria said Israeli actions were to blame for guerrilla attacks.

Israeli troops have not struck deep into Lebanon since they left six years ago after an 18-year struggle with Hizbollah.