Beijing has accused Taiwan’s intelligence agencies of carrying out “sabotage” on the mainland and reminded residents as well as students in exchange programs to stay alert and report spies.

This comes after Beijing’s rare move of airing a themed anti-Taiwanese infiltration program during evening prime time on state broadcaster China Central Television over the past week.

The CCTV on Saturday started broadcasting the first episode of a series of programs detailing cases in which Chinese students studying in Taiwan were said to be targeted by Taiwanese spies who lured them with money, sex and friendship.

A string of cases in which Taiwanese spies roped in Chinese mainland students to provide confidential information highlighted the security challenges the mainland is facing from infiltration and espionage, said the Global Times in an op-ed.

“The activities in reality are not as thrilling and exotic as they are in films and drama, but they are more covert and difficult to detect as they quietly penetrate our daily life, study and work,” it said.

There are more than 10,000 students from the mainland enrolled in programs offered by universities in Taiwan. The paper also alleges that after the pro-independence Democratic Progressive Party took office, more spies were dispatched to the mainland.

But the fact is that Taiwan and China frequently trade accusations of spying.

For instance Zhou Hongxu, a Chinese student studying in Taiwan, was last year sentenced to prison for collecting sensitive information through contacts in Taiwanese schools and government departments, and for trying to build a spy network, according to Taiwanese papers.

A spokesperson with the Chinese State Council’s Taiwan Affairs Office told Taiwan to stop prying into the work of researchers at universities, institutes and People’s Liberation Army facilities.

However, as Beijing further isolates Taiwan, Taipei is discreetly nurturing security ties with regional powers by sharing intelligence on Chinese military deployments, sources told Reuters.