With holiday shopping in full swing, at least four malls across the U.S. were evacuated Saturday as security, and anxiety, remain high following several mass shootings in recent weeks. The evacuations came during one of the busiest holiday shopping days, Reuters reported.

In the most recent case, hundreds of people were evacuated from Governor's Square Mall in Tallahassee, Florida, Saturday evening, with witnesses describing a fight that broke out during which gunshots may have been fired, local media reported. Police were on the scene investigating the incident. The case is still developing.

Earlier Saturday, approximately 500 people were evacuated from the Largo Mall near Tampa, Florida, due to a suspicious package, news reports said. The package turned out to be a suitcase.

Outside of Florida, a mall in New Jersey and one in New Mexico were also evacuated. A bomb threat was found on the walls of a restroom in the Shops at Riverside in Hackensack, New Jersey. The mall was later reopened after police cleared the area. A bomb threat found on a restroom wall in Farmington, New Mexico, closed the Animas Valley Mall for several hours before police cleared the shopping center and it reopened.

The evacuations across the U.S. come at the height of the holiday shopping season and have the potential to hurt businesses during their most important period of the year.

Heightened security measures in the U.S. reflect unease after the mass shooting in San Bernardino, California, earlier this month and the terror attacks in Paris last month. The shooting in San Bernardino left 14 people dead and 22 injured. The husband and wife responsible for the attack have been described as “self-radicalized” and had expressed allegiance to the Islamic State group, known as ISIS. The attacks in Paris left 130 people dead and at least 350 injured. ISIS claimed responsibility for the attack.

A majority of Americans are afraid a terrorist attack could happen, with polling levels not seen since after Sept. 11, 2001. Approximately 79 percent of those recently surveyed said a terrorist attack was somewhat likely or very likely in the coming months.