Authorities in Mexico are investigating the alleged extrajudicial killing of five men in the country’s northwest after a Spanish newspaper and a US broadcaster published video appearing to show them being beaten and shot.

El Pais and Univision said the incident happened on May 18 in the city of Nuevo Laredo, a city on the Unites States’ border with Tamaulipas state, in a region hit hard by violence linked to organized crime and drug trafficking.

The outlets’ published footage on Tuesday that they said captured the incident, in which soldiers apparently beat and shot at the men on a roadside.

Mexico’s general prosecutor’s office has launched an investigation in cooperation with the Ministry of Defense, according to a press release from the ministry published a few hours after the video was broadcast.

The military prosecutor is also investigating, the defence ministry said, adding that it would guarantee the soldiers enjoyed “no impunity” and “that no conduct contrary to the rule of law would be concealed”.

The footage starts with a pickup truck, apparently involved in a chase, crashing head-on into a perimeter wall at high speed.

An armoured car with a roof-mounted machine gun then bashes into the side of the truck, though at a much lower speed.

A dozen soldiers surround the stricken vehicle, before pulling out the five men as well as a large machine gun.

The soldiers then kick and beat the men, who are tied up and pulled along the ground.

They then return fire after appearing to come under attack from shooters who cannot be seen in the footage, though the soldiers seem to be unharmed.

One of the soldiers who was near the detained men started shooting at them.

Four of the men died at the scene, according to Univision.

An ambulance arrived an hour later to transport a prisoner who was still alive, but he died on the way to the hospital, the broadcaster said.

Last February in the same city, soldiers fired on a vehicle carrying seven young people apparently leaving a party and killed five of them.

Four soldiers are on trial in that case.