Venezuela reported detecting five U.S. F-35 fighter jets flying near its Caribbean coast, which Defense Minister Vladimir Padrino called a “provocation” threatening national security.

The jets were detected 75 kilometers (46 miles) from the coastline, well outside Venezuela’s 12-nautical-mile territorial waters, flying at 35,000 feet and 400 knots.

The sighting was also reported by the crew of a nearby international airliner.

The incident comes amid heightened tensions following U.S. warship deployments in the Caribbean and strikes on suspected drug-trafficking boats, which Venezuela views as an attempt at regime change, CNN has reported.

Padrino warned the U.S. that Venezuela would not be intimidated, while the U.S. recently stationed several F-35s in Puerto Rico for training exercises.