The border town of Reynosa, in the Mexican state of Tamaulipas, is under siege.
There's a three-way street war between the Mexican authorities and two drug cartels competing for the lucrative routes north into McAllen, Texas. With eight journalists having been abducted, according to the Committee to Protect Journalists, citizens have taken matters into their own hands.
Cellphones and social media such as Twitter are now their tools and their source of information.
"Shooting on the road MTY – Victoria," read one tweet.
"Situation of risk in the area of Col. Achilles Serda, Plaza. Unexploded ordinance. TAKE PRECAUTIONS," read another.
Aldo Mendez, 29, a construction manager living with his family in Reynosa, is an active Tweeter. "There are many combat confrontations between the army and the drug cartels," Mendez told ABCNews.com. "So what can we do?" he asked. "There is no info on the primetime news, local or national."
The U.S. Consular office in Reynosa was shut down in late February after reports of gun battles breaking out in the streets. The office was reopened 10 days later. In April, the U.S. Consulates in Nuevo Laredo and Piedras Negras, border towns west of Reynosa, were shut down for two days after a grenade was thrown over the U.S. Consulate fence in Nuevo Laredo. There were no injuries, but some damage was reported.
A Warden's message, information released on the U.S. Consulates website in Monterrey, said: "Some recent confrontations between Mexican authorities and drug cartel members have resembled small-unit combat, with cartels employing automatic weapons and grenades."
That message reflects the changing nature of this violence.
Bruce Bagley, Latin American affairs expert and chair of the international department at the University of Miami, has studied Mexican drug cartels and says they're fighting to take control of a $15-16 billion trade.
"We have seen Tijuana percolate up, Mexicali percolate up, and certainly El Paso Juarez percolate up -- Reynosa is one more," Bagley told ABCNews.com.
Referring to the Reynosa situation, he said, "The Zetas have been the architects of all this."
The Zetas are a cartel, many of whose members were once special forces working for the government.
"Their military training has taught them that you just don't commit the crime, but you try to control the context in which the crime is committed," said Bagley. "They are now blockading the streets, which means the police can't even get to the scene of the crime."
Also different about this violence are the hour-long firefights, known as balaceras.
"After the confrontations, the scenes look like a war zone," Mario Hernandez, another social media user and Reynosa resident, told ABCNews.com. "Some roads are fully abducted and destroyed by the cartels."
Fed up, social media users are now spreading information themselves.
"With so many death and combat situations that have never been accepted or denied by the authorities, we knew we had to take care of ourselves," said Mendez. "We created #Reynosafollow."
#Reynosafollow is a Twitter "hash tag" created by citizens to inform the community about any shootings or risky situations. If someone sees, witnesses or hears about a shoot-out somewhere in town, they log on and post it to the ongoing Twitter conversation.