Police fired tear gas on Sunday at scores of demonstrators rallying against Israel's ground offensive in Gaza as the protesters tried to reach the U.S. Embassy compound north of Beirut.
Thousands also held an anti-Israel demonstration in Turkey as news coverage of the invasion, launched late Saturday, dominated Arab satellite television stations. Many including Al-Jazeera showing live footage of the Gaza Strip and aired interviews with wounded Palestinians.
Israel's weeklong aerial bombardment of Gaza has sparked strong condemnation across the Muslim and Arab world. Thousands in cities from Tehran to Damascus have taken to the streets to protest the attacks, which have killed about 500 Palestinians and wounded more than 1,600 according to Gaza officials.
Israel says the aim of the operation is to stop the Palestinian militant Hamas group from firing rockets at southern Israeli towns.
Water hoses, then tear gas
Lebanese police first used water hoses to try to push about 250 demonstrators away from the U.S. Embassy. But when that didn't work, they fired tear gas, said Lebanese security officials.
No one was injured and the crowd dispersed, said the officials, who spoke on condition of anonymity because they were not authorized to speak to the media.
Later in the day, thousands of supporters of Hamas and Lebanon's Islamic Group held a sit-in outside the U.N. building in central Beirut. Dozens of riot police stood guard.
"This battle will end a (peace) settlement forever. This battle will show who are the men. Are they those who kiss (Israeli Prime Minister Ehud) Olmert ... or those who carry their blood on their hands," Hamas' representative in Lebanon, Osama Hamdan, told the crowd in an apparent reference to Palestinian leaders who hold talks with Israel.
Hamas is opposed to any peace settlement with Israel and calls for the destruction of the Jewish state.
In Turkey, more than 5,000 people held an anti-Israel rally in Istanbul, waving Palestinian flags and burning effigies of Olmert and President George W. Bush.
Condemnation of ground attack
Also Sunday, the leaders of Egypt and Jordan, the only two Arab countries to have peace treaties with Israel, condemned Israel's ground offensive in the Gaza Strip and called for ending Israel's attacks.
Palestinian President Mahmoud Abbas also denounced Israel's ground offensive as "brutal aggression" in his harshest words yet in describing Israel's assault on his Hamas rivals in Gaza.
Meanwhile, the leader of Lebanon's militant Hezbollah group Sheik Hassan Nasrallah discussed the situation in Gaza with visiting chief Iranian nuclear negotiator Saeed Jalili, the group's Al-Manar TV said.
Al-Manar did not give further details but said Nasrallah and Jalili, who arrived here Saturday from neighboring Syria, discussed "ways of ending this aggression."
Hezbollah, which is a strong ally of Hamas, possesses a formidable arsenal of rockets and missiles that bloodied Israel during a monthlong war between them in 2006. Hezbollah has not threatened to join Hamas in its current battle with Israel, but Nasrallah said last week that his men are on alert in case Israel attacks Lebanon.