Four US citizens were assaulted and abducted in Matamoros, Mexico on Friday, according to the FBI. The Americans were driving a white minivan with North Carolina license plates when they drew fire from unidentified gunmen. The assailants then drove away with the four victims in their grasp.

The FBI is offering a $50,000 reward for the return of the victims and the arrest of those responsible for the kidnapping. The US State Department has issued a Level 4 "Do Not Travel" advisory for US citizens in the region, citing crime and kidnapping.

The agency is cooperating with federal partners and Mexican law enforcement agencies to investigate the kidnapping. The FBI has asked members of the public with any information on the abduction to call the San Antonio Division at 210-225-6741 or submit a tip online.

The disappearance has highlighted the state of insecurity along the border between the US and Mexico, with authorities warning about the potential threat facing citizens who