The United States has issued a travel alert for Americans in Mexicali, northern Mexico, and temporarily suspended consular activities in the border city over a “potential threat,” without providing further details.

The alert was issued Monday night and advised U.S. citizens to avoid government buildings, seek shelter if an incident occurs and remain vigilant about their surroundings.

The U.S. government did not disclose the nature of the reported threat, identify who or what might be targeted, or provide information about its source.

Mexicali, the capital of Baja California state, lies directly across the border from Calexico, California, and is a major commercial and social hub between Mexico and the United States.

Mexican President Claudia Sheinbaum said Tuesday that the alert was related to the possibility of activity by a criminal group.

“There was an alert about the possibility of a criminal group,” Sheinbaum said during her regular morning news conference, adding that the information had come from U.S. agencies.

Sheinbaum said Mexican authorities had received no further details regarding the nature of the alert but urged continued vigilance and monitoring in Mexicali.

Despite the warning, the city remained calm throughout Tuesday, with no immediate reports of an incident linked to the alert.

Later Tuesday, Sheinbaum's security cabinet said authorities had not identified evidence of a specific or imminent threat to the population.

Nevertheless, authorities increased surveillance and patrols across Mexicali as a precautionary measure.

Baja California Gov. Marina del Pilar Ávila also said late Tuesday that Mexican authorities remained active and that security operations would be reinforced in the state capital.

The measures come as authorities maintain heightened attention to security threats in the border region, where criminal organizations have historically operated and where cross-border trade and movement are extensive.

Mexicali, home to more than 1 million people, is among the largest cities along the Mexico-U.S. border. Its proximity to Calexico gives the city significant economic and social importance, with substantial daily cross-border movement.

While the United States has not provided details about the reported threat, Mexican authorities have so far said they have found no specific or imminent danger to the public.

Security forces are expected to maintain an increased presence in the city while authorities continue to assess the information that prompted the U.S. travel alert and temporary suspension of consular activities. (ILKHA)