BEIJING - China on Friday scrambled fighter jets to monitor a dozen US and Japanese military aircraft which entered its new air defence zone, state media said.
Beijing's announcement last weekend of the air defence identification zone, which covers islands at the centre of a dispute between China and Japan, has raised tensions in the region.
The report indicated that Japan and the US are continuing to disregard Beijing's demands that aircraft submit flight plans when traversing the zone in the East China Sea or face unspecified "defensive emergency measures".
"Several combat aircraft were scrambled to verify the identities" of US and Japanese aircraft entering the air defence zone, the official Xinhua news agency said, quoting air force spokesman Shen Jinke.
The Chinese aircraft, which included at least two fighter jets, identified two US surveillance aircraft and 10 Japanese aircraft including an F-15 warplane, Shen said.
The Pentagon said on Friday that American forces would continue normal operations, despite China's latest move.
"We'll continue to partner with our allies in the region and operate as normal," Lieutenant-Colonel Erik Brine, a Pentagon spokesman, told AFP without elaborating.
The US, South Korea, Japan and other countries have accused Beijing of increasing regional tensions with its new air defence zone.
Shen said the air force had a mission to monitor foreign aircraft inside the zone "throughout the entire process, with timely identification".
Japan and South Korea both said on Thursday they had disregarded the ADIZ, showing a united front after US B-52 bombers also entered the area.
But Beijing is facing considerable internal pressure to assert itself. China's state media called on Friday for "timely countermeasures without hesitation" if Japan violates the zone.
Washington has security alliances with both Tokyo and Seoul, and analysts say that neither China nor Japan -- the world's second- and third-biggest economies, and major trading partners of each other -- want to engage in armed conflict.