Lebanese police said the planes hit the airport road, which crosses through the southern district considered a Hezbollah stronghold.
A Lebanese army official said bombs also hit two bridges in the southern suburbs of the capital and a stadium.
Earlier, Israel had dropped leaflets warning residents to stay away from the Hezbollah offices in southern Beirut, where Hezbollah leader Sheik Hassan Nasrallah is thought to live.
Israeli planes also bombed the main highway between Beirut and the Syrian capital of Damascus.
Hezbollah guerillas on Thursday lobbed dozens of Soviet-era Katyusha rockets into northern Israel. Rockets also landed in the northern port city of Haifa, which would mark the deepest point into Israel that Hezbollah rockets have ever reached, but Hezbollah denied that they fired the rockets.
An Israeli diplomat called the rocket attacks "a major escalation" in the violence.
Israeli airstrikes and artillery hammered hundreds of targets in Lebanon, including two strikes on the Beirut airport, where helicopter gunships left craters in runways and turned fuel tanks into fireballs.
Israel said it targeted the airport because it is a transfer point for weapons and supplies to Hezbollah. The airport was closed and all flights were diverted.
The violence began Wednesday when Hezbollah forces crossed into Israel, killing three soldiers and abducting two others.
Since that cross-border raid, five more Israeli soldiers have been killed, as well as two Israeli civilians, two Lebanese soldiers and 45 Lebanese civilians, according to Israeli and Lebanese sources.
Despite the fact that several countries -- including the Unites States and Lebanon -- have said that the Lebanese government doesn't have the capacity to extend its authority into Hezbollah-held territory, Israel has blamed the Lebanese government for the violence and charged it with the soldiers' safe release.
Hezbollah, which enjoys substantial backing from Syria and Iran, is considered a terrorist organization by the United States and Israel. The group holds 23 of the 128 seats in Lebanon's parliament.
Maj. Gen. Udi Adam, head of Israel's Northern Command, said Wednesday he had "comprehensive plans" to battle Hezbollah throughout Lebanon, not just in the Islamic militia's southern stronghold.
The attack on the Beirut-Damascus highway -- where witnesses said hundreds of tourists were lined up on the Syrian border in an attempt to flee Lebanon -- follows several Israeli attacks on what appear to be strategic targets.
On Wednesday, Israel said its air force had conducted more than 100 airstrikes on Hezbollah bases and weapons-storage facilities, and on roads and bridges that could be used to transport the kidnapped soldiers.
In addition to Thursday's attack on Beirut's Rafik Hariri International Airport, Israel also targeted Rayak Air Base in the Bekaa Valley near the Syrian border and a small military airport in Qulayaat in northern Lebanon, according to Lebanese army sources.
Israeli Ambassador to the U.S. Daniel Ayalon told CNN Thursday night that Israel's attacks are intended to "de-fang the Hezbollah so that they will not have the capabilities to launch their rockets ... and hopefully this will strengthen the Lebanese government so that they will exercise their sovereignty" in the south of the country, where Hezbollah is virtually autonomous.
Israeli warplanes struck the al-Manar television station, too, which the Israel Defense Forces said Hezbollah uses to incite and recruit activists. A broadcast tower was destroyed and three people were injured, but the station continued its broadcasts, said al-Manar Editor Ibrahim Moussawi.
Israeli warships set up a blockade, preventing cruise ships from docking in Beirut and cutting off the delivery of fuel used to operate Lebanese power plants.
When the violence will end is unclear, as neither side seems willing to relent.
Ayalon, who called the Haifa attacks a "major escalation," said there was no timetable for Israel's offensive in Lebanon.
"We will have to continue with the operation until there is no capability of the Hezbollah to do what they are doing."
Israeli Defense Minister Amir Peretz said Israel won't let Hezbollah, a Shiite Muslim militia, return to the border -- raising the prospect that Israel may again occupy southern Lebanon, as it did from 1978 to 2000.
Under the treaty that ended Lebanon's 15-year civil war in 1990, Hezbollah was allowed to retain its weaponry to fight Israeli troops in southern Lebanon. It says it won't disarm until Israeli troops leave the disputed Shebaa Farms region near the Syria border, which the United Nations recognizes as Syrian territory.
Naim Qasem, Hezbollah's deputy secretary-general, said Thursday that Hezbollah members have the right to remain on "any part of Lebanese soil."
"We intend to send a clear message that we wish not to escalate this conflict by killing civilians," Qasem said. "But we know that Israel will not stop its aggression until it feels pain. Therefore, they should learn from what happened today. They have failed to protect their cities and their civilians."
Nasrallah has defended the abductions of 31-year-old Ehud Goldvasser and 26-year-old Eldad Regev as Hezbollah's "natural, only and logical right." He further said that the soldiers had been taken "far away" and that no Israeli military campaign would secure their release.
Nasrallah wants to enter negotiations on a prisoner exchange, a demand Israel has rebuffed, saying it would encourage more kidnappings.
Israel has exchanged prisoners with Hezbollah before, most recently in 2004 when Israel handed over more than 400 Palestinian, Lebanese and Arab prisoners for an Israeli businessman and the bodies of three Israeli soldiers.
In an attempt to defuse the situation, the U.N. has sent three envoys to Cairo to meet with Egyptian officials and consult with Arab League foreign ministers, who will convene Saturday. The U.N. Security Council will hold an emergency meeting Friday at the request of Lebanon, France's U.N. Ambassador Jean-Marc de La Sabliere said.
In Straslund, Germany, President Bush said Israel has a right to defend itself -- but he urged it not to weaken Lebanon's government, in place since 2005 elections that led to the withdrawal of Syrian troops. (Full story (http://edition.cnn.com/2006/POLITICS/07/13/bush.germany/index.html))
"The democracy of Lebanon is an important part of laying a foundation of peace in that region," Bush said during a stop on his way to the Group of Eight economic summit. He added that Syrian President Bashar al-Assad "needs to show some leadership toward peace."
Imad Moustapha, the Syrian ambassador to Washington, took issue with the remarks and with what he called the Bush administration's "flagrant bias toward Israel."
"The only party to blame for this collision of violence in the Middle East is Israel itself, with its continuous occupation and with the atrocities it has committed against the Palestinians, particularly in the past two months," Moustapha said. "Now, suddenly, it is Damascus once again, and it's Iran once again. Who is to blame for the results of their occupation?"
Amid the rising violence, the U.S. State Department has given embassy and non-emergency personnel permission to leave Lebanon. The department also advised U.S. citizens to put off travel there.