Reynosa, Tamaulipas — Authorities are reporting a "situation of risk" at the prison located this city's southern outskirts.
The report came from city officials via Twitter feed about 8:20 p.m. Tamaulipas state police officials refused to provide further details about the incident via telephone late Friday evening, instead referring phone calls to the attorney general's office in Reynosa.
A spokesman there did not answer phone calls that night. Officials with the city's police department also did not answer calls.
Meanwhile, city officials are advising residents to avoid the area via Twitter and Facebook updates.
"Even if you do not hear detonations, the situation of risk remains," city officials posted on the social networking Web site. "Please take precautions."
Earlier this year, authorities also investigated an apparent shooting at the Cereso Dos state prison on Reynosa’s southern outskirts.
Tamaulipas state police also announced via Internet that five people were killed during a battle between an armed gang and Mexican army soldiers early Friday morning.
The shootout occurred in the Lomas de Jarachina Sur neighborhood on the southwest side of Reynosa. Information about possible casualties among soldiers was not disclosed.
Friday morning's fatalities followed what had already been a violent week in Tamaulipas’ border cities. The deaths pushed the body count to at least 25 among armed people battling authorities across the region since Tuesday, authorities confirmed.
Authorities have said the Gulf Cartel and the Zetas — the two dominant drug smuggling groups in the region — have been fighting each other and authorities as the once-allied cartels vie for control over smuggling routes into the United States.
Federal police continue to investigate Friday’s battle.
Suspected drug cartel members launched coordinated attacks at military installations in Tamaulipas border cities Tuesday, resulting in 18 fatalities, two injuries and seven arrests among attackers that day, the Mexican Defense Ministry said late Wednesday night.
Nearly 13,000 rounds of ammunition, scores of grenades, guns, and several rocket launchers and improvised explosive devices were among the weapons soldiers seized after the Tuesday attacks.
Defense officials said only one soldier was hurt — he lost a thumb while under attack.
The Tuesday attacks came amid blockades across Reynosa, reportedly set up by gunmen who forced bus and truck drivers to block main roads with their vehicles. Several blockades were set up near the Mexican army base along Highway 2 to prevent soldiers from patrolling the city, Defense Ministry officials said.
At least one man was killed during a confrontation with troops Wednesday while soldiers and armed men exchanged gunfire near Boulevard Colosio in the Nuevo Amanecer neighborhood in north Reynosa.
City officials also reported two shootouts Thursday afternoon near the Broncos bridge — the namesake of Reynosa’s pro baseball team, which plays in the adjacent stadium. At least one man was killed during those attacks.
Street violence has surged in cities across from South Texas at least since mid-February, killing scores of suspected cartel members.
More than 18,700 people have been killed in Mexico since President Felipe Calderón launched a crackdown on organized crime in late 2006, Mexican daily El Universal reported Thursday. The 958 slayings in March made it the most violent month since 2005, when the war between organized crime groups in the country escalated.