MEXICO - While murders have dropped across Mexico, a burst of violence has rattled the capital's suburbs, with criminals dumping bodies on roadsides, kidnapping people in broad daylight and levying protection taxes.
The crime surge in the State of Mexico, which wraps around the capital like a horseshoe, has challenged President Enrique Pena Nieto's pledge to reduce the murders, kidnappings and extortion plaguing his nation.
The state's governor, Eruviel Avila, has described the crime wave as "rare and temporary," the violent reaction of gangs dismantled by a police crackdown.
Other officials say part of the problem may be linked to what Mexicans call the "cucaracha" effect, when sweeps against drug cartels in one state cause criminals to scurry like cockroaches to neighbouring regions.
This has again revived fears that the gangland violence seen elsewhere could infect Mexico City, which remains a relative oasis from such mayhem.
"Part of the problem is this: The state of Mexico has eight borders," the state's public safety secretary, Rocio Alonso Rios, told AFP.
"This has complicated the situation," she said, noting that her state neighbours Michoacan, Guerrero and Morelos, all known for drug cartel violence.
But security experts say the country's most populous state has struggled with violence for a long time, even during Pena Nieto's time as governor from 2005-2011.
"It is the norm, and permanent," said Alejandro Hope, a former intelligence official and security expert at the Mexican Institute for Competitiveness.
After more than 70,000 people died in drug-related violence under his predecessor's six-year term, Pena Nieto has indicated that murders have dropped since he took power in December 2012.
But Mexico State is bucking this downward trend. It has seen 374 homicides in the first two months of the year, up from 303 in the same period last year, according to official figures. Kidnappings and extortion have also increased.
The state government has responded by dismantling 14 kidnapping gangs and deploying state police to highways and cities, including 1,000 officers who man checkpoints in Cuautitlan Izcalli, just a half hour drive north of Mexico City.
The suburb of 600,000 people has recorded 38 murders since January, the majority appearing with execution-style bullet wounds.
"From January until nine days ago we had a constant problem of executions. Not one week passed without an execution," Mayor Hector Karim Carvallo Delfin told AFP on Monday.
"It was a very difficult issue; people were very afraid. This had never happened to us," he said, blaming the problem on the infamous "cucaracha" effect.
The mayor said bodies were abandoned in public view, some accompanied by letters signed with the words "Gulf Cartel," a drug gang based in northeastern Mexico. Other signs were found in the city warning that the cartel was now in charge.
But Carvallo Delfin said the gangland killings stopped a week ago, after authorities detained a band of 12 people accused of murder, kidnapping and drug dealing.
The gang was rounded up last week after three of its members kidnapped a man near Cuautitlan Izcalli, leading to a daytime car chase with police and a shootout that left a 14-year-old girl and 50-year-old man dead, authorities said.
On a recent afternoon, some 20 state police officers checked buses and frisked passengers in a rough part of the city.
"This is very good. We are full of criminals," said Jose Rosas, a 61-year-old bag factory supervisor who has been robbed three times at gunpoint since January.
At a small grocery store up the road, shopkeeper Ismael Hernandez said a man walked in last month and threatened to end his "protection" unless he got paid.
"Crime continues despite the (state police) operation," the 50-year-old said.
Other towns around Mexico City, a metropolis of 20 million people, have witnessed similar brazen criminal acts.
Milenio television broadcast dramatic security camera footage of an attack on a karaoke bar in Netzahualcoyotl last month, when five gunmen stormed out of a car and opened fire, killing two people.
Francisco Rivas, director of the National Citizens' Monitor, a civil society organisation that tracks crime, said the problem could be worse because Mexico State has underestimated its statistics in the past, only to revise them later.
For Rivas, the state must tackle the high level of corruption as part of its crime-fighting efforts.
"We are very worried because we don't see a plan to resolve the issue of impunity," he said.