China accused Taiwan Monday of expanding a rocket test facility on the island, which state-run media claimed will be the largest missile base in Asia.

The People's Daily, flagship newspaper for the Communist Party and mainland government, said a large hardened bunker is under construction at the Jiupeng missile testing ground. The paper, citing Taiwan news sources, said the facility will deploy Patriot III anti-missile systems purchased from the United States upon completion in 2005.

The base, located in Taiwan's mountainous Pingdong County, is said to be controlled by the Zhongshan Scientific Research Institute under the island's defense ministry.

The People's Daily called it one of three mysterious units of the Taiwan military developing nuclear, biological and chemical weapons. The other two were identified as Preventive Medicine Research Institute and Nuclear Energy Research Institute.

The mainland paper warned the facility carries out covert activities, which American and French spy satellites have been unable to penetrate.