Cars were attempting to cross the border from Mexico into the United States on Wednesday when loud speakers announced a drill was being conducted and agents swarmed, closing it down.

Facebook user Pedro Alejandro Preciado Monroy posted several videos of the seemingly impromptu drill in Tijuana, Mexico:

Motorist sat on the hoods of their cars as police and other agents pulled strings of razor wire across the roadway. Some honked, to no avail.

Another video showed of police in riot gear fanning out to block any attempt to cross the border.

As an alarm went off, officers donned gas masks. One man appeared to take a selfie as clouds of smoke wafted behind him.

The last video shows flash bang grenades going off.

Several countries, including Italy and Norway, have closed their borders due to coronavirus. Will the United States be next?