A rocket slammed into a suburb of Beirut on Friday, bringing the conflict in neighboring Syria closer to Lebanon's bustling capital and reviving bitter memories of the country's own devastating civil war.
With skirmishes between Shiites and Sunnis on the rise around the country, religiously mixed and highly vulnerable Lebanon is increasingly buffeted by powerful forces that are dividing the Arab world along sectarian lines.
There were no casualties from the rocket, which struck a Christian area southeast of Beirut overnight, but the incident raised fears that Lebanon was being sucked into a war that has already paralyzed state institutions and strained its economy with the presence of more than a half-million Syrian refugees.
"This is very, very dangerous," said Pierre Ashkar, head of a syndicate of hotel owners, referring to the potential damage to the tourism industry from such rocket attacks. He said his daughter and her husband were among scores who have canceled plans to come Lebanon.
"When our kids can't come to Lebanon, I don't know how a French, British or even a Saudi and Kuwaiti can," he told The Associated Press.
For the most part, Lebanon has stayed on the sidelines of the Arab Spring, keeping up its appearance as an oasis of relative stability, which has helped its tourism and entertainment businesses.
The Lebanese — and the tens of thousands of expatriates and Gulf Arab tourists who visit every summer — have learned to live with the country's occasional bouts of upheaval and violence, including huge street protests that followed the assassination of a former prime minister in 2005 and deadly street clashes in 2008, when the militant Shiite Hezbollah group briefly overran parts of Beirut.
Beneath the surface lurk the same forces that devastated the country in its years of civil war, with simmering hatreds still dividing Muslims and Christians, Sunnis and Shiites, and secular and fundamentalist groups.
The Lebanese civil war began in 1975 with clashes between mostly Muslim Palestinian factions and Christian militiamen, and eventually turned into a Christian-Muslim civil war in which external players like Saudi Arabia, Syria and Western countries used the country as a battleground.
The uprising in Syria against President Bashar Assad, which began in March 2011, brought sectarian tensions to the surface and has inflamed rivalries.
The two countries share a complex web of political and sectarian ties, and Lebanon is deeply divided into pro- and anti-Assad groups, a legacy of Syria's long dominance of its small neighbor.
Lebanon's Sunni Muslims mostly back the overwhelmingly Sunni rebels in Syria, while many Shiites support Assad, who is a member of Syria's minority Alawite sect, an offshoot of Shiite Islam.
Sectarian tensions sharply increased after the Shiite militant group Hezbollah openly joined Assad's forces in fighting the rebels seeking his ouster. Lebanon has seen repeated bursts of violence, but it has mostly been restricted to border areas and the northern city of Tripoli.
Rockets from Syria fall regularly into towns and villages near the border. Last week, the tensions exploded into street clashes in the southern city of Sidon, suggesting the scope of the fighting was widening.
Friday's rocket slammed into a valley southeast of Beirut, causing a blast that reverberated across large parts of the city and surrounding mountains.
After hours of searching, Lebanese soldiers found the rocket in Jamhour, a Christian area near the presidential palace, the Defense Ministry and the Hezbollah stronghold of Dahyeh, the military said in a statement. Two rocket launchers still holding one rocket also were found about 10 miles (15 kilometers) to the north of the city, also in a Christian town.
It was the second such attack in less than a month. Two rockets hit Dahyeh on May 26, wounding four, hours after the Hezbollah leader Sheik Hassan Nasrallah vowed in a speech to help propel Assad to victory.
The gap widened when Hezbollah fighters were instrumental in a recent Syrian government victory as they helped pro-Assad forces regain control of the strategic town of Qusair near the Lebanese border.
No one claimed responsibility the rocket attacks near Beirut, but rebels in Syria have vowed to retaliate and have sent rockets slamming into Hezbollah strongholds in northeastern Lebanon.
Friday's attack may also have been an attempt to drag Christian areas into the conflict, or perhaps was intended to send a message to Lebanese President Michel Suleiman, a Christian.
Rebel groups have warned Suleiman to rein in Hezbollah. Under pressure, the president has been increasingly critical of Hezbollah involvement in Syria; on Thursday, he said the group was making a "mistake" and urged it to leave Syria.
The conflict has paralyzed Lebanese institutions.
In downtown Beirut, Lebanese protesters continued a sit-in for a second day Friday near the parliament building to demand elections that originally were scheduled in June. Their chants on both evenings were drowned out by music blasting from a nearby rooftop nightclub, a sign of Beirut's bon vivant lifestyle struggling to prevail.
Last month, the 128-member parliament extended its term by a year and a half, put off the balloting because of the deteriorating security conditions in the country.
The demonstrators, who clashed with police Thursday, say the extension was unconstitutional. They have set up tents, blocking a side road in the city center.
Ali Jammoul, a 22-year-old activist and biology student taking part in the sit-in, said he fears the Shiite-Sunni sectarian hatreds will lead to a cycle of revenge killings even uglier than Lebanon's civil war, which is believed to have killed 150,000 people.
"The Lebanese are hostage to external dictates. They are spectators waiting to see what is going to happen in the battle (for Syria)," he said, adding that Lebanon, with its weak government, was powerless to stay out.
Ashkar, the tourism official, said Beirut is typically packed in the summer with more than 100 percent capacity but now is at only 40 percent occupancy, most of them business travelers. Hezbollah's public involvement in the war in Syria, he said, was a big blow to the industry that contributes 20 percent to the national income.
"This is really the worst season" since 1992 after the restoration of the tourism industry following the end of civil war, he said.
For the first time in years, all of Lebanon's hotels, with their 22,000 rooms, are partially closed or operating at reduced capacity, he added.
The tension has risen to a point where politicians on TV talk shows regularly throw invectives, and sometimes water glasses, at each other, or engage in a few fistfights.
The violence prompted organizers of Lebanon's famous Baalbek International Festival to announce plans to move the annual music show out of the ancient city with its Roman ruins because of its proximity to the Syrian border. Earlier this month, 18 rockets and mortar rounds fired from Syria hit the area, about 15 kilometers (10 miles) from the Syrian frontier.
"The situation in Baalbek does not permit holding the festival, and we are now looking for a new venue," an official with the festival said Friday, speaking on condition of anonymity because the official was not authorized to talk to reporters.
At least one participant, American soprano Renee Fleming, has canceled a planned concert at the festival, which is usually held under the towering columns of the Roman Temple of Jupiter, citing deteriorating security conditions. The festival is scheduled to begin in August.
Many Lebanese have despaired over the violence and the country's future.
"Half of my family left recently," said Jammoul, who was among bottle-throwing protesters who clashed with police overnight.
"My brother was my comrade in the streets. ... I cried when I returned to the streets after a week and he wasn't next to me, when I got beaten and he wasn't near me," he said.
Associated Press writer Bassem Mroue contributed to this report.