But Syria blamed Denmark for the violence. The Danish government should have apologized for the caricatures, published in the Danish independent newspaper Jyllands-Posten, said an editorial in Syria's state-run daily newspaper. The Danish prime minister and Jyllands-Posten apologized last week if the cartoons gave offense, but upheld the newspaper's right to print them.
And many Lebanese suspected Syria's hand in the streets of Beirut on Sunday. After sending soldiers into Lebanon during the civil war, Damascus remained the de facto ruler of its neighbor for years before withdrawing its soldiers last spring. Even now, many Lebanese complain of Syrian meddling and blame Damascus for a string of political assassinations, including the death last year of former Prime Minister Rafik Hariri in a bombing that also killed 22 others on a Beirut street.
A U.N. commission investigating Hariri's assassination has implicated top Lebanese and Syrian security officials.
"These are people who want to destabilize the country," said Lebanese Tourism Minister Joseph Sarkis, who drove through the Christian neighborhoods under armed guard to appeal for calm as the riots quieted down. "They are receiving orders from the source we all know to provoke a clash between the communities."
Lebanon's Grand Mufti Mohammed Rashid Kabbani also blamed infiltrators for the violence, which he called an attempt to "harm the stability of Lebanon."
Lebanese have been warning for months that Syria might try to provoke unrest by tampering with Lebanon's delicate religious balance.
"Syria wanted to make another war in Lebanon, and they want the war to be between Christians and Muslims again," said Michel Saouma, a 34-year-old sales manager. "So they did this thing to show the world that the people of Lebanon cannot live by themselves."
Of the more than 170 protesters arrested, 76 were Syrian, Reuters reported. An additional 38 were Lebanese, 35 were Palestinian and 25 were stateless Bedouins.
As the riots raged, many Muslim clerics appealed to the crowd for calm. One Muslim stood in front of a Greek Orthodox church to protect it from the mob.
Meanwhile, a 2,000-strong security force fired off hundreds of canisters of tear gas, shot live rounds into the air and sprayed water cannons.
When the demonstrators finally were pushed out, Christians gathered in the streets, still hazy from tear gas and smoke. Some of them wept from anger as they swept up the chunks of broken glass. Many described the rioting as an assault on their faith, and an unwelcome reminder of the battles of religious militias during Lebanon's 1975-1990 civil war.
"Why bring it here? We have nothing to do with it," said Salim Seoud, a 43-year-old truck driver. "We feel awful about what happened in Denmark, but why bring it to the streets of Lebanon? We're trying to get away from these kinds of problems."
Some accused the Lebanese government of leaving them at the mercy of the mob. The demonstration had been publicized for days, with leaflets and calls from mosques.
"This is very dangerous. It shows that they could do anything, go to any home, kill anybody," said Johnny Kairouz, a 25-year-old who works at an advertising agency. "The internal security failed at the easiest test they've had. This was open and planned, and it could have been prevented."
Solemn and defiant, Christians flocked to the damaged church by the hundreds. A woman with a rosary prayed silently over a shattered window; inside, altar boys and priests prepared for an evening Mass. But on the street, young men waved flags that are symbols for civil war militias.
The scene was a stark contrast to a year ago, when Hariri's assassination drove thousands of Lebanese into the streets, chanting for religious tolerance and unity against the Syrians.
"They came for the Danish Consulate, but it became Christian against Muslim. We thought there was national unity, but there is no national unity," said a 29-year-old hairstylist named Elie Diab, who stood outside the church while chants rang into the night.
"If they want to confront us, we're ready to fight face to face," Diab said. "If we are forced to fight, we will. We have enough weapons, thank God."
He turned to the man next to him, an older gentleman in a tweed jacket.
"There's no Christian that doesn't have a weapon at his place, isn't that true?" Diab asked.
"Of course," the other man replied.