REYNOSA, Mexico -- A car explodes outside a police station, another outside a television station. A drug gang is suspected of massacring 72 migrants. A prosecutor investigating those deaths suddenly disappears.
Mexico's drug cartels seem to be adopting the tactics of war zones half a world away.
The violence has contributed to fewer migrants crossing the border into the U.S., officials say, because they have to traverse some of Mexico's most dangerous territory to get to Texas. Mexican officials, meanwhile, warn there likely will be more bloodshed in the coming months.
"Violence will persist and even intensify," President Felipe Calderon said Friday at a forum on security where he vowed he would not back down.
The two car explosions happened early Friday morning less than 45 minutes apart in Ciudad Victoria, the capital of the northern state of Tamaulipas near where the slaughtered migrants were found.
The first exploded in front of the offices of the Televisa network and the second in front of transit police offices. There were no injuries, though both caused some damage to buildings, and the Televisa blast knocked out the network's signal for several hours.
The network described the explosion as a car bomb, but the state attorney general's office could not confirm that.
If the explosions were car bombs, it would mean a total of four so far this year in Mexico -- a new and frightening tactic that officials say the cartels are using in the escalating drug war.
The prosecutor, Roberto Jaime Suarez, disappeared Wednesday, a day after the 72 bodies were discovered at a ranch outside the northern town of San Fernando, officials said. A transit police officer in the cartel-dominated town was also missing.
No drug gangs claimed responsibility for the violence.
But the massacre's lone survivor, 18-year-old Luis Freddy Lala Pomavilla, said the killers identified themselves as Zetas, a group started by former Mexican army special forces soldiers and is now a lethal drug gang that has taken to extorting migrants.
Lala, who is recovering from a gunshot wound to the neck and is under heavy guard, told investigators the migrants from Central and South America were intercepted on a highway by five cars, according to his statement that The Associated Press had access to Friday.
More than 10 gunmen jumped out and identified themselves as Zetas, Lala said. They tied up the migrants and took them to the ranch, where they demanded the migrants work for the gang. When most refused, they were blindfolded, ordered to lie down and shot.
Lala's mother, who lives in the United States with her husband, said she spoke to her son Friday for the first time since the attack. She said she'd been trying to reach him since he didn't arrive at their home as scheduled.
"Every afternoon, I was buying phone cards to call the coyote (smuggler) and find out where my son is," she said. "I did nothing but call and call and call, and there was never an answer."
Then a Mexican hospital worker called and told them their son had been in "an accident."
The AP is not identifying the woman or her location because of potential danger.
Lala has been offered a humanitarian visa that would allow him to stay in Mexico, Immigration Commissioner Cecilia Romero said Friday. But his mother said he was pleading for her to help him get to the U.S.
Investigators have identified 31 of the dead migrants, whose bodies were taken to Reynosa, a city across the border from McAllen, Texas. Those identified include 14 Hondurans, 12 Salvadorans, four Guatemalans and one Brazilian.
The migrants were killed Sunday, Honduran Deputy Foreign Minister Alden Rivera said, citing a Mexican government report. The bodies were already decomposing when Mexican marines found them Tuesday, bound, blindfolded and slumped against a wall at the ranch outside San Fernando.
Rivera said only the 31 identified dead carried documents. Investigators are collecting DNA from the rest, but Rivera said it may be impossible to identify more.
Meanwhile, the bodies of 14 people were found dumped in various locations around the Pacific Coast resort of Acapulco on Friday, and the bodies of eight people who had been shot and burned were found in a car outside the border city of Ciudad Juarez.
The U.S. State Department issued a new warning for Americans living or traveling in Mexico, particularly in border cities. U.S. diplomats in the northern industrial city of Monterrey were told to move their children out of the area -- which is also plagued by fighting between the Zetas and its rivals -- after a deadly shootout last week in front of the American Foundation School, where many American students are enrolled.
The Mexican government, however, continued to stress that violence is limited to certain parts of the country.
Government security spokesman Alejandro Poire broke the wave of violence down to seven conflicts, and said 80 percent of more than 28,000 drug-related killings since late 2006 have been confined to just 162 of nearly 2,500 Mexican cities.
Kidnappings and attacks on government security patrols are rampant on the highways surrounding San Fernando. Last month, the bodies of 15 people were dumped in the middle of the road from San Fernando to Matamoros, a city across the border from Brownsville, Texas.
Drug gangs have terrorized news organizations in the area, where journalists have been killed and newspaper offices attacked to quiet coverage.
In Tamaulipas, many newspapers and TV stations have simply stopped reporting on the violence. The day after the massacre was discovered, local newspapers carried headlines about the new school year. Even the national Mexican media have covered the story without bylines, as did the Brownsville Herald in Texas.
Mexico's "increasing insecurity" has contributed to a sharp drop in the numbers of migrants in Mexico over the past year, the immigration commissioner said. But Romero said the U.S. economic slump and tighter border security are the main factors.
Mexican immigration agents have rescued 2,750 migrants this year, some stranded in deserts and others who were being held captive by organized crime gangs, Romero added. In Tamaulipas, alone, agents rescued 812 migrants kidnapped by drug gangs, she said. Many of those migrants told authorities the cartels tried to force them into drug trafficking.
"We perhaps saved them from being massacred like the 72 that we lost this time," she said.