The Pentagon said two Chinese jet fighters unsafely intercepted a U.S. naval surveillance plane over the South China Sea in the second such incident around China’s shores in a week.

Cmdr. Gary Ross, a Pentagon spokesman, said in a statement that the two Chinese J-10 fighters intercepted a U.S. Navy P-3 aircraft in international airspace on Wednesday. He didn’t provide the exact location.

“The aircrew deemed the intercept unsafe and unprofessional. Operations were able to continue unimpeded,” he said. “We continue to review the facts of this incident and will convey our concerns through appropriate channels with the Chinese government.”

China’s foreign and defense ministries didn’t respond to requests for comment.

The Communist Party’s main newspaper, the People’s Daily, said in a commentary on its English-language website on Saturday: “How ridiculous it is for the U.S. Navy to complain after jeopardizing China’s security and interests. Such behavior makes one think of a Chinese idiom: The wicked are the first to complain.”

It added: “If you come to China’s door looking for trouble, then don’t complain about it afterward.”

The intercept occurred on the same day that a U.S. Navy ship sailed within 12 nautical miles of a Chinese-built artificial island in the South China Sea for the first time since President Donald Trump took office.

The USS Dewey, a guided-missile destroyer, came within six nautical miles of Mischief Reef and conducted a man-overboard drill on Wednesday in a freedom-of-navigation operation challenging excessive maritime claims, U.S. officials said.

China’s Defense Ministry said the operation had disrupted efforts to reduce tensions in the region and that two Chinese destroyers had warned the U.S. ship to leave the area.

Mischief Reef is the site of one of seven artificial islands that China has built in the past three years in the Spratlys archipelago, where its claims are contested by Vietnam, Malaysia, Brunei, Taiwan and the Philippines, a U.S. ally.

The U.S. and its Asian allies and partners fear that China could use the islands, some of which have airstrips and antiaircraft weapons, to enforce its claims and impede freedom of navigation on the world’s busiest sea lanes.

Beijing has also stepped up naval and coast guard patrols around islands in the East China Sea that are claimed by both China and Japan but controlled by Japan, and has tried to enforce an air-defense identification zone covering that area since 2014.

Last week, two Chinese SU-30 jet fighters conducted another unprofessional intercept with a U.S. WC-135 surveillance plan in international airspace over the East China Sea, according to U.S. officials.

China’s Defense Ministry said the U.S. aircraft was conducting surveillance over the Yellow Sea and Chinese jets responded by investigating in accordance with law. It also blamed security problems between Chinese and U.S. forces on U.S. reconnaissance activities in the region.

In 2015, the U.S. and China reached an agreement on rules of behavior during air encounters following a series of midair confrontations, some of which were dangerous.

In 2001, a Chinese jet fighter crashed, killing the pilot, after it clipped the wing of a U.S. EP-3 surveillance aircraft over the South China Sea. The U.S. plane was forced to land on the Chinese island of Hainan, where the crew was detained for 11 days, triggering a diplomatic crisis.

China has repeatedly demanded that the U.S. ships and aircraft cease surveillance operations close to its shores. The U.S. says such activities are allowed anywhere in international waters and airspace.

“U.S. forces operate in the Asia-Pacific region on a daily basis, including in the South China Sea,” Cmdr. Ross said on Friday. “All operations are conducted in accordance with international law and demonstrate that the United States will fly, sail, and operate wherever international law allows.”