Heavy gunfire erupted near a key US-Mexico border crossing with local reports suggesting multiple people were killed.
The incident broke out on the Pharr–Reynosa International Bridge at around 1.30pm local time on Wednesday (May 10).
The Mexican Secretariat of National Defence (SEDENA) and US authorities confirmed there was an armed confrontation.
Hidalgo Police Chief Romero Rodriguez confirmed four people died and it is believed those confronting the police had cartel connections.
Weaponary was seized including five long weapons, three vehicles with handmade armor, weapons and cartridges, and tactical equipment, reports Telemundo40.
According to the information, 5 people involved fled the scene.
The bridge across the Rio Grande connects the city of Pharr in Texas, US, with the city of Reynosa in the Mexican state of Tamaulipas.
Footage taken from within one of the trucks on the bridge shows what appeared to be Mexican army vehicles zooming past drivers cowering in their vehicles.
In another video, two people cower by the side of a truck as a barrage of shots ring out over the seemingly deserted road.
One witness has shared a picture of a crumpled bullet saying: "Bullets bouncing off the Reynosa-Pharr customs facility"
The border regions of Mexico are hotly contested by the notorious cartels that control the supply of illegal drugs into the US.
Local reports suggest the clashes broke out after authorities allegedly arrested 'La Pawa', the regional leader of the criminal group Los Zetas.
Joe Biden has said hewill send 1,500 troops to the US-Mexico border, in response to fears a wave of immigrants will try to cross when Covid-19 border restrictions lift later this month.
The 90-day deployment of troops will support the US border patrol but will not carry out law enforcement duties.
Tamaulipas state in the city of Matamoros was where the 'Tummy Tuck' Four were kidnapped leading to the death of two of them.
US citizens Latavia “Tay” McGee and Eric James Williams survived and returned to their families, while Shaeed Woodard and Zindell Brown were killed.
Mr Brown's sister, Zalandria Brown of Florence, South Carolina, said that the four friends, who were really close, were aware of the dangers in Mexico.
It is believed they were mistaken for Haitian drug dealers.
The cartel released an apology over the incident.
