WASHINGTON — Chinese warplanes, in a dangerous maneuver, intercepted a U.S. Navy patrol plane flying a routine mission over the South China Sea on Tuesday, according to the Pentagon.

The incident is the latest in a series of unwelcome encounters between the Chinese military and U.S. military aircraft and ships in the region where China has increasingly asserted claims of sovereignty. It has filled in slivers of land in the sea to build landing strips and has challenged American naval vessels in international water.

"Initial reports characterized the incident as unsafe," according to a Pentagon statement. It occurred in international air space during a routine patrol.

Tuesday's encounter ran counter to the trend over the last year in which Chinese pilots had been flying in "a safe and professional manner," according to the Pentagon.

Air Force Gen. Herbert "Hawk" Carlisle said in a recent interview that the Chinese intercepts seem geared toward pushing U.S. warplanes farther from their shores. Buzzing U.S. patrol planes is dangerous, and in 2001 resulted in a mid-air collision with a Chinese fighter.

The Navy P-3 patrol plane was severely damaged and forced to land on the Chinese island of Hainan. One Chinese fighter pilot died when his plane crashed. The crew of 24 naval aviators was held by the Chinese for 11 days.

A similar incident is likely to happen if the Chinese continue to intercept American planes aggressively, Carlisle said.

"If they continue to become more and more aggressive, the potential (exists) for a miscalculation or a safety incident," Carlisle said. "We've worked hard to prevent another P-3 and Hainan island situation. We've seen some of their aggressive maneuvers against our aircraft that are operating in international airspace. That's dangerous. And there's the potential miscalculation or some kind of safety incident that could potentially spiral into a very bad situation."