A retired Taiwanese lieutenant colonel was sentenced to four years in prison for spying for China, a court said Thursday, in the latest of a spate of espionage allegations involving the two sides as tensions grow. Tu Yung-hsin was convicted on Wednesday of violating national security laws by trying to build a spy network for Beijing and recruit another lieutenant colonel by giving him money and gifts. That colonel, Tsai Liang-chung, was not charged as he refused Tu's request to film a video pledging loyalty to Beijing and turned in the money he received to the authorities, according to a statement by the New Taipei District Court. Tu can appeal the ruling and remains free for now. The case came as Chinese state media said Beijing's security agents have cracked down on "hundreds" of spying cases linked to Taiwan and arrested "a batch of Taiwanese spies and their accomplices". The state broadcaster CCTV has also aired four television "confessions" by Taiwanese nationals currently detained by China's opaque judicial system. China regards democratic Taiwan as its own territory and has vowed to one day bring the self-ruled island back into the fold, by force if must. Beijing has ramped up pressure since the 2016 election of President Tsai Ing-wen who regards the island as a de facto sovereign nation and not part of its "one China". Taiwan's Premier Su Tseng-chang on Tuesday accused Beijing of "creating terror" with its recent state media reports and televised confessions. The alleged Taiwanese spies included Czech-educated scholar Cheng Yu-chin, who was arrested in April 2019, according to CCTV. His appearance on TV came weeks after a visit to Taiwan by a group of Czech politicians which infuriated Beijing. China's People's Daily on Thursday published a letter warning Taiwanese intelligence agents against "playing with fire". "Our country's national security agencies have firm will, ample confidence and sufficient capabilities to beat and severely punish any infiltration activity by Taiwan's intelligence units," it said. Multiple Taiwanese nationals have disappeared into Chinese custody accused of various anti-state crimes in cases that have caused an outcry at home. Authoritarian China's judicial system is notoriously opaque and answers to the Communist Party. Rights groups say forced and televised confessions are commonplace. aw/jta/je