Early Thursday morning, a Mexican law enforcement helicopter flew into American airspace over Arizona and fired on U.S. Border Patrol agents. There were no injuries, and no equipment was damaged.

U.S. officials said Mexico quickly apologized, and called the incident "a mistake," the Los Angeles Times reports. According to Tucson's KVOA, the helicopter was flying a drug interdiction mission.

A border patrol representative told TIME that the helicopter operators fired two shots:

"At approximately 5:45 a.m. Thursday morning, a Mexican law enforcement helicopter crossed approximately 100 yards north into Arizona nearly 8 miles southwest of the Village of San Miguel on the Tohono O'odham Indian Nation while on a law enforcement operation near the border," Peter B. Bidegain III, a spokesman for the United States Border Patrol, said in an email. "Two shots were fired from the helicopter but no injuries or damage to U.S. property were reported. The incident is currently under investigation."

[Image via AP]