Four Americans who were kidnapped in Mexico remained missing Tuesday as authorities in both countries continued to search for them and piece together the motive in the brazen abduction.
The US citizens vanished Friday in an attack carried out by multiple gunmen in the northern Mexico border city of Matamoros, the FBI said.
The Americans were in the country’s Tamaulipas state, south of Brownsville, Texas, when the group of unidentified men unleashed a barrage of bullets on them after they crossed the border in a white minivan.
US and Mexican officials confirmed Monday that a Mexican citizen was killed during the melee.
Here’s what we know so far about the kidnapping.
How did the kidnapping happen?
The Americans The gunmen were encountered shortly after crossing the border in a minivan with North Carolina license plates, according to Special Agent Oliver Rich, who is in charge of the FBI’s San Antonio Division.
Shortly after, unidentified gunmen fired upon the passengers in the vehicle, and the four Americans were placed in a pickup and taken from the scene by the men.
A woman driving in Matamoros who asked not to be identified for fear of reprisal told the Associated Press she witnessed what appeared to be the shooting and abduction: The white minivan was hit by another vehicle near an intersection, then gunfire rang out, the woman said. Another SUV rolled up, and several armed men hopped out.
“All of a sudden (the gunmen) were in front of us,” she said. “I entered a state of shock, nobody honked their horn, nobody moved. Everybody must have been thinking the same thing, ‘If we move they will see us, or they might shoot us.'”
Who are the Americans kidnapped in Mexico? What to know about victims
Law enforcement has not released the identities of the American victims, but Zalandria Brown of Florence, South Carolina, said she has been in contact with the FBI and local officials after learning that her younger brother, Zindell Brown, is one of the four victims.
“This is like a bad dream you wish you could wake up from,” she said in a phone interview to the Associated Press. “To see a member of your family thrown in the back of a truck and dragged, it is just unbelievable.”
Tamaulipas’ chief prosecutor, Irving Barrios, said a Mexican woman died Friday in the attack but it was not clear whether she was connected to the kidnapping.
Why were the victims in Mexico?
Zalandria Brown said her brother, who lives in Myrtle Beach, and two friends had accompanied a third friend who was going to Mexico for a tummy tuck surgery. A doctor who advertises such surgeries in Matamoros did not answer calls seeking comment.
Brown said the group was extremely close and they all made the trip in part to help split up the driving duties. They were aware of the dangers in Mexico, she added, and her brother had expressed some misgivings.
“Zindell kept saying, ‘We shouldn’t go down,'” Brown said.
Mexican President Andrés Manuel López Obrador said Monday that the four Americans were in the country for medicine.
A TREK FOR HEALTH CARE:4 kidnapped Americans crossed into Mexico to buy medicine, says Mexican president
Video appears to show attack
A video posted to social media Friday showed men with assault rifles and tan body armor loading the four people into the bed of a white pickup in broad daylight.
One was alive and sitting up, but the others appeared either dead or wounded. At least one person appeared to lift his head off the pavement before being dragged to the truck.
How are US, Mexican authorities responding?
US Ambassador to Mexico Ken Salazar said various US justice agencies were working with their Mexican law enforcement counterparts to recover the missing victims.
On Monday, Mexican army soldiers gathered in Matamoros and began a search mission for the Americans.
White House press secretary Karine Jean-Pierre said President Joe Biden is aware of the situation and is “closely following the assault and kidnapping.”
Jean-Pierre declined to answer other questions, citing privacy concerns.
The FBI is offering a $50,000 reward for any information leading to the return of the missing US citizens and the arrest of those responsible for the incident.
The US State Department has issued a “Level 4: Do Not Travel” advisory for US citizens in Tamaulipas, citing crime and kidnapping there.
Contributing: Associated Press.
Natalie Neysa Alund covers trending news for USA TODAY. Reach her at nalund@usatoday.com and follow her on Twitter. @nataliealund,