Mexico removes unauthorized U.S.-marked signs from Playa Bagdad near Matamoros as binational probe intensifies

With the American president publicly stating he would be “OK” with attacks on Mexico to destroy drug cartels, diplomatic alarm bells began to ring when warning signs allegedly placed by the U.S. Department of Defense appeared on Mexican sovereign soil south of Matamoros.

Mexican naval forces removed the six signs Monday that claimed U.S. Department of Defense ownership over a portion of Playa Bagdad. The beach is a coastal area in Tamaulipas near the Río Grande, an environmentally sensitive region also known to be frequently controlled by cartels that are alleged to use the spot for the transshipment of narcotics.

Environmentalists raised alarms over the installation of the warning signs after a group claimed to have witnessed what appeared to be soldiers arriving from the United States.

According to Conibio Global, a local environmental organization, a field technician saw several men cross the river from the U.S. by boat and plant metal stakes bearing bilingual “Restricted Area” warnings. The signs stated that the land had been declared restricted “by authority of the commander” under a directive from the U.S. Secretary of Defense and referenced U.S. internal security law.

The Mexican Navy (SEMAR) removed the signs, including some placed in the water, and later issued a joint statement with the Foreign Ministry confirming they found no immediate evidence that the postings were officially authorized by U.S. authorities.

The U.S. Department of Defense has, however, declared the Rio Grande Valley “defense area III,” which is a categorization that the American military uses when needed to justify actions in the region.

Mexico’s Foreign Affairs Ministry said it has reached out to the U.S. Embassy to investigate, while its section of the International Boundary and Water Commission (CILA) will conduct a technical review to clarify the border demarcation.

Local officials and environmental advocates sharply criticized the move. The mayor of Matamoros, Horacio Ortiz Juarez, called the deployment of signage “an illegal trespass and a violation of national sovereignty.”

Conibio Global emphasized that the area is crucial for wildlife, warning that foreign-installed restricted-area markers could limit conservation efforts and access to key habitats.

Tamaulipas Gov. Américo Villarreal has requested a technical study to confirm the current course of the Río Bravo, as river shifts may affect where the international border lies.

President Claudia Sheinbaum confirmed that a U.S. entity acknowledged hiring a company to install the signs. She said Mexican and U.S. authorities are working to resolve the matter “with clearer information and instrumentation” about the exact border in this part of Tamaulipas.

Shifts in the river course have frequently led to disagreements regarding the actual international border between the two countries, though the recent claims by Washington regarding possible military action against Mexican cartels have escalated Mexico’s concerns about possible invasions of its sovereign territory.