China's prototype stealth fighter has made its first-known test flight, marking dramatic progress in the country's efforts to develop cutting-edge military technologies.
The plane, dubbed the J-20, flew for about 15 minutes over an airfield in the south-western city of Chengdu where it was spotted carrying out runway tests last week, according to reports.
Photos of the plane in flight and on the ground surrounded by men in civilian clothes and army overcoats were also posted on unofficial Chinese military websites. A J-10 fighter - China's last home-grown jet - flew behind it as a chase plane.
The test flight came as US defence secretary Robert Gates was visiting the country, and the normally secretive military made no attempt to hide it or remove photos and reports about the J-20 from the internet. The timing and hands-off approach is apparently intended to send the message that Beijing is responding to calls from the US and others to be more transparent about its defence modernisation and future intentions.
Although probably many years from entering China's inventory, the J-20 is a potential rival to the US F-22 Raptor, the only stealth fighter currently in service. The US is also employing stealth technology on the F-35 Joint Strike Fighter, while Russia's Sukhoi T-50's stealth fighter made its maiden flight last year and is set to enter service in about four years.
In the photos, China's twin-engine J-20 appears larger than either the Russian or US fighters, potentially allowing it fly farther and carry heavier weapons.
The J-20 would pose the greatest immediate threat to Taiwan, the self-governing island which Beijing claims as Chinese territory - to be recovered by force if necessary. Taiwan's air force is composed mostly of ageing US F-16s and French Mirage jets, and its electronic warning systems would find it difficult to cope with stealth technology.
A Chinese stealth fighter would "seriously undermine the Taiwan air force's advantages", said Alexander Huang, of Taipei's Tamkang University.
China's aviation industry - both military and civilian - has made rapid progress in recent years but still relies heavily on imported technology. Propulsion has been a special problem, with Russian engines still powering the J-10 and J-11, a copy of Russia's Su-27 fighter.
Chinese progress also potentially calls into question Mr Gates's decision to cap production of the F-22 at 187 planes, partly because of claims that China would not have a fifth-generation fighter for years to come.