Beijing threw down the gauntlet to Washington yesterday, announcing it had successfully tested an advanced missile-interception system - a week after the US decided to sell arms to Taiwan despite strong protests. Xinhua announced the news last night in a terse, one-sentence statement saying: 'On January 11, 2010, China conducted a test on ground-based mid-course missile-interception technology within its territory.' The Ministry of Foreign Affairs immediately issued a statement saying the test was 'defensive in nature and not targeted at any country'. However, military analysts said it was a strong response to the US decision to sell Patriot air defence missiles to Taiwan. 'This is certainly related to Taiwan,' said a Shanghai-based military analyst who declined to be named. 'China understands verbal protests are not enough. The test is going to touch a raw nerve with people at the Pentagon. This is the Chinese military telling the US: watch out, we are getting there.' What Beijing tested yesterday was a complex anti-missile system that consists of a ground-based missile interceptor capable of shooting down an incoming ballistic missile in space and a radar network that could precisely track and monitor fast-moving, incoming warheads. The United States has been pursuing similar technology, known as the Ground-based Midcourse Defence (GMD) system. It is the cornerstone of America's national missile defence strategy. The US military has conducted 14 intercept tests - only eight successfully. The technology is so costly and complicated that Washington cancelled new tests last year due to repeated delays in the project. Each GMD intercept test is estimated to cost between US$115 million and US$160 million, according to the US-based Centre for Defence Information. While military experts had been speculating that Beijing was seeking similar technology, yesterday was the first time that China had announced a successful test. For a GMD system to be effective, it must both detect and track warheads, and shoot them down. A Hong Kong-based observer of the mainland military said the announcement showed the People's Liberation Army had achieved major breakthroughs on both fronts. It was not clear last night if the Chinese test was a 'radar characterisation test' - meaning the military successfully detected and tracked incoming warheads but did not fire a missile interceptor, or a live interceptor test, actually shooting down an 'enemy' missile in space. 'The test is one-upmanship from Beijing, reminding Taiwan the military balance is tilting inevitably towards the mainland,' the Shanghai-based analyst said. Yesterday's news came hard on the heels of Taiwanese media reports that the island planned to buy eight second-hand Perry-class frigates from the US to boost its naval defences. Taiwan's China Times reported yesterday that the island's Defence Ministry had also sought to buy other advanced technology from the US to build its own version of the Aegis Combat System in a bid to replace Jiyang-class (Knox-class) frigates that have served for 30 years. The Taipei-based newspaper described the plan as an attempt to 'revive' a similar proposal to build a home-grown, hi-tech radar system that was abandoned 15 years ago because of pressure from Beijing and budget constraints. The island's Defence Ministry said it would replace the frigates but it had yet to single out a specific model for replacement. The China Times said the Perry-class frigates were targeted because the island already had such vessels, known as Cheng-Kung class, and it would cut maintenance costs. A second-hand Perry-class frigate would cost only about 20 per cent of a new one, it added, which would be affordable for the island. Beijing was upset by Washington's announcement last week that it would sell Patriot missiles to Taiwan, as part of a deal signed under the previous US administration. In the space of three days, the foreign affairs and defence ministries made five official denunciations. In the latest protest, Deputy Foreign Minister He Yafei told Xinhua on Saturday that the arms sale last week had seriously violated the three Sino-US joint communiques, including the principles established in the Joint Communique in 1982.