The Mexico kidnapping incident, involving four Americans and the murder of two of them in the border city of Matamoros, led to the accusation of five alleged members of a powerful Mexican cartel on Friday on charges of aggravated kidnapping and murder.

The Attorney General's Office of Tamaulipas announced the allegations a day after the Gulf Cartel was blamed for the kidnapping.

In a handwritten message left on the truck's windshield, the five men claimed to be members of the Gulf Cartel, the major organized crime gang in this region of Mexico.

The note was discovered alongside the five men when they were tied up close to the pickup truck on Thursday morning, ABC News noted.

The note apologized for their acts and claimed that a few Gulf Cartel members were behind the kidnapping and murders.

"We have decided to deliver those involved and directly responsible," the note said, presumably referring to the five men tied up at the scene.

Authorities around Mexico, including the armed forces, rushed to the situation.

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Mexico Kidnapping Victims Took the Wrong Route

The four Americans were traveling to a doctor's appointment less than three hours after crossing the border, according to new livestream footage captured by one of the Mexico kidnapping victims and retrieved, geolocated, and analyzed by CNN.

The GPS navigation clock, the length and direction of the shadows, and the van's proximity to the bridge indicate that the video was captured a few minutes after 9:18 a.m. when the Tamaulipas attorney general alleges the group crossed into Mexico.

Given its remoteness and GPS navigation, how the four got there was unclear. The GPS routes in the video show that they were heading to Washington McGee's doctor's appointment.

The group never made it to the doctor's appointment, said a U.S. authority familiar with the investigation. The group called the doctor's office to say they were late for the 7:30 a.m. appointment.

The video was taken from Eric Williams' Facebook Live, and CNN got it from a friend who requested anonymity for safety reasons.

Although the video helps provide an additional timestamp of where the four were before their abduction, it does not explain where they went for three hours instead of their scheduled doctor's visit.

Surveillance footage almost a mile south of the doctor's office shows the vehicle at 11:12 a.m. when the attorney general of Tamaulipas claims it was last seen.

Then, a grey Volkswagen Jetta started following the van between 11:12 and 11:38, as stated by the attorney general, adding that several vehicles also followed the van by 11:41 a.m.

The Mexico kidnapping suspects from the Gulf cartel attacked the Americans around 11:45 a.m.

President Andres Manuel Lopez Obrador Rejects Military Intervention Against Mexico Cartels

Political leaders in the United States, particularly Republicans, expressed their displeasure with the Mexico kidnapping incident that involved four Americans, said Reuters.

Although President Andres Manuel Lopez Obrador vehemently opposed using military force against the cartels in Mexico, some took it as a reason to push for it.

U.S. Ambassador to Mexico Ken Salazar has likewise rejected the possibility of military involvement.

"Some proposals have been put on the table, talk about a military force in Mexico. It's not going to bring us the solutions that we need," he told reporters on Friday.

Authorities are investigating whether the members of the Gulf Cartel kidnapped the four foreigners out of fear that they would invade the gang's territory, said a government document.

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This article is owned by Latin Post.

Written by: Bert Hoover

WATCH: New details emerge in Mexico kidnapping deaths of 2 U.S. citizens - From CBS Evening News