BEIRUT, Lebanon -- Even for the war-hardened Lebanese, four explosions in two weeks are too much to cope with. Once-vibrant cafes lie empty, shopping malls are virtually deserted and late-night dining has been put on hold. In a movie theater, a woman watching the Will Smith comedy "Hitch" gets a cell phone call about a blast and exclaims "Infijar?!" ("Explosion?!"), whereupon a dozen people quietly head for the door.

Outside the United Nations offices, workers fill sandbags and erect barriers. At a Beirut mall, newly hired private security guards check vehicles' trunks and engines and slide a mirror beneath the chassis looking for explosives. Restaurants put up roadblocks to keep cars from parking too close.

Fear is gripping Lebanon following a recent spate of bombs placed under or near cars that have killed three people and injured 24. The sense of security built up over years of postwar calm has been shattered, with rumors of bombs and suspicion of unclaimed bags feeding the hysteria.

"This brings back such bad memories," said Lina Haddad, 34, sitting on her balcony one night overlooking the empty streets. "I'm afraid to leave home. I look at every parked car and wonder if it will explode." She puts her children to bed in a windowless room.

Car bombings -- 3,641 of them that killed 4,386 people -- were a hallmark of Lebanon's 1975-90 civil war but have been rare since. Many are too young to remember them. Lebanon is enjoying a tourism boom and a steady return to its prewar glory as a commercial hub.

All that changed with the explosion that killed former Prime Minister Rafik Hariri and 19 others on a Beirut seafront street Feb. 14. The assassination shook Lebanon and touched off demonstrations against Syria and its 28-year troop presence in Lebanon. Counter-demonstrations in support of Syria followed, but Damascus nonetheless was forced to begin withdrawing its troops.

No one knows for sure who was behind the subsequent bombings. Anti-Syrian leaders blame Damascus and allied Lebanese security authorities, saying they are meant to show that Lebanon cannot cope without the Syrian army. The pro-Syrian camp blames saboteurs, saying they are destabilizing the country to invite international intervention.

The turmoil has raised fears of a return to civil war. So far, however, the political camps do not conform to the religious boundaries that figured in the 1975-1990 conflict. This time, there are Christians and Muslims on both sides of the debate.

But the bombings have all happened in Christian areas.

On March 19, an explosion wounded nine people and destroyed shops in the commercial area of Beirut's New Jdeideh suburb, a Christian opposition stronghold. Four days later, another explosion devastated a shopping center near the port city of Jounieh in the Christian heartland north of Beirut, killing two people and injuring two.

On March 26, a blast went off in an industrial zone in the Christian Beirut suburb of Bouchrieh, injuring five people and setting factories ablaze.

And the latest came Friday night, targeting a shopping and residential center in the resort of Broummana in the pinewooded mountains overlooking Beirut and the Mediterranean coastline. Seven people were slightly injured.

"Where next?" is a question on everyone's mind. Suspicious cars or bags are reported daily. The fear has even overcome the Lebanese's love of a late-night dinner on the town.

"We are seeing something like a 70 percent decline in business," says Walid al-Arabi, manager of the Scoozi restaurant.

Like other shoppers, Maha Assaf, a 23-year-old computer graphics student, was subjected to a car and handbag search before being let into a Beirut mall.

"This is supposed to make me feel safer," she said, "but to be honest it's frightening." (AP).