Two rockets have struck the Israeli city of Haifa, hours after a threat by the militant Lebanese group Hezbollah.
Hezbollah denied firing any rockets at the northern port - Israel's third largest city. There were no reports of injuries or damage.
Later, Lebanon's international airport was hit for a second time as Israel continued attacks by land, sea and air.
About 50 people have died in the Israeli raids, launched after Hezbollah captured two Israeli soldiers.
Most of the dead are civilians.
The fresh attacks on Beirut airport set at least one fuel tank ablaze.
The airport was already closed following Israeli air strikes earlier on Thursday.
'Haifa attack'
Hezbollah had said it would attack Haifa if Israeli planes bombed Beirut.
It had fired dozens of rockets into Israel in the past two days, killing at least two Israelis and injuring dozens.
But until the Haifa attack none had gone further than 20km (12 miles) inside the country.
Haifa is more than 30km (18 miles) from the Lebanese border and had been thought to be out of Hezbollah's range.
Israeli police said two rockets had fallen on a Christian area of Haifa called Stella Maris.
The Israeli ambassador in Washington, Danny Ayalon, described the Haifa incident as a "major escalation" of the crisis.
He said the international community should make it clear to Iran and Syria - who both have links with Hezbollah - that they were "playing with fire".
Meanwhile the UN Security Council has arranged an emergency meeting for Friday at Lebanon's request.
Israeli losses
Lebanese ministers have called for a ceasefire with Israel, saying that all means should be used to end "open aggression" against their country.
ISRAEL IN LEBANON
International calls for restraint are growing, with Russia, France and the EU saying Israel's response to the capture of two soldiers was disproportionate.
US President George W Bush described Hezbollah as a "group of terrorists who want to stop the advance of peace".
Speaking in Germany, he said Israel had the right to defend itself, but its action should not weaken the Lebanese government.
Israeli government spokesman Mark Regev said Israel was responding to "an unprovoked act of aggression" by Lebanon.
The offensive follows a day of heavy fighting in which the Israelis suffered their worst losses on the border for several years.
Eight soldiers were killed and two were injured, in addition to the two captured in a Hezbollah ambush.
The operation comes as Israel continues a separate offensive in the Gaza Strip. An Israeli soldier was captured in a cross-border raid into Israel by Palestinian militants from Gaza last month.
ISRAEL BLOCKADES LEBANON
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©
~RS~q~RS~~RS~z~RS~18~RS~)