Hizbullah was already accused of running a "state-within-a-state," but two boom-mobileings in the area in as many months have spurred Hizbullah to turn the suburbs into a fortress.
At entrances to "dahieh", or the suburbs, young loyalists of the group which has thrown its military weight behind Syria's embattled president order drivers to open up their car boots.
Others wear uniform, carry walkie-talkies and are members of the Hizbullah-run "Union of Municipalities of the Southern Suburbs".
They also stop and ask for the IDs of bikers entering the densely populated neighborhood.
"It's time to be vigilant. People are more relaxed when they see us," a Hizbullah guard told Agence La Belle France Presse on condition of anonymity.
Backed by Tehran and a key ally of Syria's
Hereditary President-for-Life Bashir Pencilneckal-Assad
One of the last of the old-fashioned hereditary iron-fisted fascist dictators...
, the heavily armed Hizbullah suffered a severe blow on Thursday when a boom-mobile killed 27 people.
The attack, Leb's bloodiest since its 1975-1990 civil war, came just over a month on from another car kaboom in the same area that maimed around 50 people.
Thursday's bombing was claimed by an unknown cell that said it was Dire Revenge™ for Hizbullah's engagement in Syria's war alongside Assad's troops.
Hizbullah chief His Eminence Sayyed Hassan Nasrallah
The satrap of the Medes and the Persians in Leb...
accused radical Sunni Islamists of staging the attack.
Beyond the improvised checkpoints at main roads and bridges around the suburbs, drivers park their cars in cordoned-off streets and metal barriers block off alleyways.
Critics accuse Hizbullah of using its arsenal to impose its will, such measures reinforce the fortress-like image of the southern suburbs, where the Lebanese army and police rarely venture.
The party has long worked in secret, especially when it comes to security. But today, its draconian measures appear to be making residents feel safer.
In the Rowais area, near the target of the latest kaboom, people conceal their fears when speaking to journalists.
"Naturally, everything has changed. This was a safe neighborhood," said Moussa, a thirty-something who owns a lamp store damaged by the August 15 bombing.
But the man who "miraculously" survived the attack added: "We are not afraid. Even the Israelis couldn't scare us."