The heavily armed rebels usually show up in groups of 20 or more, dressed in green fatigues and seeking food.
"Of course you have to give it to them," said one resident of this isolated village 35 miles west of the Colombian border. "People don't like that they're here, but with few police and many informants around, they keep quiet."
Then just as suddenly, the rebels with the Revolutionary Armed Forces of Colombia, or FARC, melt back into the jungle.
Over the last decade, the leftist insurgents have regularly spilled over into Panama, seeking rest and respite from pursuing Colombian armed forces. But rarely have they appeared as frequently or penetrated so deeply into Panamanian territory as in recent months, say residents and officials here in Darien province.
And guns aren't all they're bringing with them.
Panamanian and U.S. officials say it's no coincidence that drug-related violence has risen in tandem with the more frequent sightings of the guerrillas, whom the State Department labels drug traffickers and terrorists.
U.S. counter-narcotics officials believe that the FARC and other Colombian traffickers are shipping more drugs from Colombia overland across Panama to avoid tighter control of Pacific and Caribbean coastal waterways by the Panamanian and U.S. naval forces.
All this has Panamanian and U.S. officials concerned that Panama could become the next battleground in narco-wars that have convulsed parts of Mexico, Guatemala and Honduras.
"Before, drugs in Panama were seen as a U.S. problem. Now officials here see it more as a common cause," said one foreign counter-narcotics official who was interviewed this month in Panama City.
Whether it's because of the drug trade or more aggressive pursuit by Colombian troops, the increased presence of the FARC on Panama's side of the Darien rain forest is indisputable, several locals said.
"In the last year or two, you really notice them more," another El Real resident said this month. "They come around to buy necessities -- rice, beans, salt and milk -- and they always pay. They don't involve themselves in local disputes and other issues. But they have their informants who tell them if the police are coming."
Like others interviewed for this story, El Real residents spoke on condition of anonymity for fear of FARC reprisal.
They have good reason. In early April, rebels killed a Colombian refugee in nearby Boca de Cupe in front of his three children, leaving a note pinned to his chest inscribed with the word sapo -- Spanish slang for "snitch."
There have been other violent incidents. In December, Panamanian border police killed a FARC guerrilla and captured another in a shootout a few miles west of the border.
The new emphasis on overland drug routes is unleashing bloody struggles for control among competing narcos for the Panamanian corridors, authorities say. Homicides in the capital are up by nearly 40% in recent years, due in part to the booming drug trade, officials say. In 2007 and '08, cocaine seizures in Panama totaled 120 tons, a big increase from previous years.
In April, two suspected members of Colombia's so-called Office of Envigado cartel were abducted as they left Panama City's swank Metro Plaza shopping mall. Their decapitated bodies were found outside the city. Authorities suspect Mexican narcos with the Sinaloa cartel were responsible.
The drug trade has spawned a new generation of gangs in the capital that are paid "in kind" with cocaine by the FARC and other traffickers for doing their legwork.
A recent census turned up the presence of 108 gangs in the country, a revelation to authorities who thought Panama was immune to a problem that has spawned crime waves in Guatemala, El Salvador and Honduras. Many of the gangs are thought to have links to the FARC.
In reaction, the U.S. Embassy has launched a $4-million anti-gang program that is funded from the Merida Initiative, the anti-drug aid package that was passed by Congress mainly to help Mexico fight the cartels.
In an e-mailed statement to The Times, U.S. Ambassador to Panama Barbara J. Stephenson said: "We strongly believe that the situation in Panama argues for working with at-risk youth to prevent gang violence from taking root, and for training the police in community policing principles so they form strong ties with their communities -- a proven recipe for preventing crime."
Rising violence in Panama was the No. 1 issue on voters' minds during presidential elections held this month, pollsters said. Supermarket magnate Ricardo Martinelli won the election in part because his campaign promise to get tough on crime resonated with voters.
Kraul is a special correspondent.