The admission came in a report by the official Xinhua News Agency saying President Xi Jinping had signed an order awarding honorary titles to all pilots in the first squadron to conduct take-off and landing tests aboard the Liaoning, China's only aircraft carrier.

"Two test pilots of the squadron sacrificed their lives during the tests," the report said. No details were given.

The original Xinhua report ran Aug. 28, but went largely overlooked at the time. It was picked up by U.S. defense blogs and linked Friday to the blog of the U.S. Naval Institute.

Carrier flight operations are inherently risky, and the loss of two pilots is far from unusual. However, China's military still operates under a shroud of secrecy and no deadly accidents relating to the carrier had been reported at the time.

China announced it had begun flight tests on the Liaoning in late 2012, spurring a wave of patriotic pride in the country's growing capabilities. State television ran hours of footage of planes landing and taking off, while Internet users across the country posted photos of themselves recreating the carrier flight crews' "all-clear" signal to the pilot.

Chinese carrier pilots fly the J-15 fighter-bomber, a copy of Russia's Sukhoi Su-33.

China spent a decade refurbishing a derelict Soviet-era carrier bought from Ukraine before commissioning it as the Liaoning in 2012. It is part of a major expansion of the Chinese navy that includes sophisticated new surface ships and submarines. The ship is slower and smaller than U.S. aircraft carriers and doesn't carry as many aircraft.

The Liaoning is still conducting sea trials and Chinese defense officials haven't said when, or even if, it will receive its full complement of aircraft.

On Dec. 5, 2013, a Chinese ship accompanying the Liaoning was involved in a near collision with a U.S. Navy cruiser, the USS Cowpens, when it was operating in international waters in the South China Sea. U.S. Navy officials said the Cowpens maneuvered to avoid the collision, but it marked the two nations' most serious sea confrontation in years.