As Lebanon reels from deadly bomb attacks that revived painful memories of the civil war, jittery authorities are banking on a smartphone application and other alert systems to prevent further bloodshed.
The attacks -- twin car bombs in the northern city of Tripoli last week and a blast in a densely populated Shiite area of Beirut eight days before -- have shaken the Lebanese just as a military strike on neighbouring Syria appears imminent.
"See that car?", said Khairy Ghali, a 22-year-old waiter in a near-empty restaurant on Beirut's popular Hamra Street, pointing to a vehicle parked in front of the establishment's outdoor terrace.
"We don't know if there's anything in it... We're afraid, we come to work and we don't know if we'll go home or not."
Not content with the usual measures aimed at preventing further attacks, such as checking car trunks before vehicles enter vulnerable sites like malls and hotels, authorities have also decided to harness the power of smartphone technology.
The Lebanese army has launched an application called "LAF Shield" that allows citizens to take videos or photos of suspicious vehicles or objects and send them to the army command.
It also allows them to identify "dangerous sites" such as places where security incidents happened through an interactive site.
In a statement on its official website, the army said it aimed "to involve the largest numbers of citizens in defending the country."
Authorities have also called on people to put their names and telephone numbers in a visible place on their cars every time they park them, and more generally for residents to be ultra vigilant.
For the moment, the methods are working... almost to a fault.
"The operation room of the Internal Security Forces (the country's police) has been receiving more than 1,000 calls every day since the Beirut bombing from citizens all over Lebanon who tell us there are suspect cars," a security official told AFP.
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"In some cases, it's clear that the vehicles are not suspect. Other times, police have to break windows and force open doors to inspect the vehicle," said the official, who wished to remain anonymous.
"But so far, all have been false alerts."
Photos circulating widely on social media also show signs posted on windscreens by jumpy drivers keen to avoid damage to their vehicles.
"It isn't booby-trapped. I'm nearby and will come back quickly," read one sign posted online.
The attacks on August 15 and August 23 killed more than 70 people, and brought back painful memories of the 1975-1990 civil war, when people regularly checked under their cars before getting in.
Lebanon has been the scene of several car bombings since 2005 when Prime Minister Rafiq Hariri was assassinated, but last week's twin car bombs in Tripoli were the bloodiest attacks since the end of the civil war.
Some residents of Beirut are now hesitant to leave their neighbourhoods for fear that a parked car they walk by will blow up.
Shop and restaurant employees in the normally busy Hamra Street -- one of the capital's main thoroughfares -- say they are seeing far fewer customers than in normal times.
And as if that was not enough, a strike on neighbouring Syria now appears more and more imminent, amplifying fears.
US President Barack Obama on Friday gave his clearest indication yet that a military intervention would happen soon to punish the Syrian regime, which it believes unleashed poison gas in an alleged attack last week that killed more than 1,400 people.
"It's all very close, there will be consequences here," said Sharif Alaa, a 26-year-old Lebanese on holiday in his home country from Paris, where he lives.
"There are political parties that are very close to Syria, and there will be consequences for the economy too," he said on the streets of Beirut.