Chinese Jets Intercept U.S. Navy Plane

An American intelligence aircraft was intercepted over the South China Sea and involved in a midair collision that has left one Chinese pilot missing and relations between China and the U.S. tense.

United States military officials are demanding the immediate return of the American plane whose mission was to gather radar frequencies and radio traffic from China's air defense.

China immediately blamed the U.S. aircraft for the collision off Hainan Island. But the commander of U.S. Pacific military forces said that the slower U.S. plane was more likely to have been hit by the nimble Chinese fighter.

"Under International Airspace rules, the fast more maneuverable aircraft [the Chinese jets] has the obligation to stay out of the way of the slower aircraft," said Admiral Dennis Blair, in charge of U.S. Pacific Military Forces. "Our aircraft fly routinely straight and level. It's pretty obvious as to who bumped into whom."

Emergency Landing on Hainan Island

A Navy surveillance plane, carrying a 24-member crew, made an emergency landing on Hainan Island without any apparent injuries to the crew, U.S. officials said.

The surveillance plane collided with Chinese fighter jets at about 9:15 a.m. local time today, which is 8:15 p.m. ET Saturday. The fighter jets were sent to intercept the American plane. The Chinese government said at least one of its fighter jets crashed and its pilot was missing.

China officials said the American plane veered and that its nose and left wing hit the Chinese plane. After initial speculation that the mid-air bump was intentional, U.S. officials said they believed the collision was an accident.

A search was on for China's downed plane and its crew.

The U.S. ambassador to China, Adm. Joseph Prueher told reporters that all 24 military personnel on the aircraft are safe. U.S. diplomats plan to visit China tomorrow. As of Sunday evening there was still no word about the return of the crew and their EP-3 surveillance plane filled with classified electronic eavesdropping equipment.

The EP-3, a four-engine propeller plane, was damaged, thus forcing it to issue a mayday call and land at a military airport in Lingshui on Hainan Island, located in southern China, officials said.

Early reports from China quoted Chinese officials as saying the American four-engine propeller plane was in Chinese airspace, and the accident was caused by the American plane. Chinese authorities had said they are reserving the right to demand compensation later.But later reports indicated the plane was flying nearly 60 miles from Chinese air space.

Conflicting Stories Raise Tension

According to the Chinese reports, a Chinese jet was conducting normal flight operations south of Hainan Island when the American plane suddenly appeared. They say the American plane hit the Chinese plane, which then crashed into the ocean.

American officials have said the Americans appear uninjured, and the Chinese appear to be responsive to requests to treat the flyers well. White House Spokesman Ari Fleischer said he expects the Chinese to return them promptly.

"That is our expectation," he said. "That is the standard practice. We would expect them to follow it."

Pentagon officials have expressed concern about the situation, especially since the EP-3 plane utilizes technology that is considered more advanced than what the Chinese military uses, possibly posing a security risk.

"We expect that their government will respect the integrity of the aircraft and well-being and safety of the crew in accordance with international practices, and that they'll expedite any necessary repairs to the aircraft and that they'll facilitate the immediate return of the aircraft and crew," said a Navy spokesman, Lt. Col. Dewey Ford, at Ft. Smith in Hawaii.

One Pentagon source called the EP-3 plane "highly classified, the most sensitive aircraft in the U.S. inventory."

The U.S. Embassy in Beijing "communicated our concern about the incident" to the Chinese government, said Col. John Bratton, a spokesman for the U.S. Pacific Command in Hawaii. U.S. authorities in Washington contacted the Chinese Embassy there as well.

ABCNEWS' Barbara Starr, Josh Gerstein and John McWethy in Washington and Chito Romana in Beijing contributed to this report.