TAIPEI, Reuters – Taiwanese authorities have raided ten Chinese tech companies accused of poaching chips engineers and other talent. This is the latest clampdown against Chinese businesses to preserve its chip dominance.

Taiwan is home to the chipmaker giant TSMC, and accounts for most of the top semiconductor production capacity in the world. Taiwanese authorities have intensified a campaign against illegal poaching by Chinese firms. This was seen as a threat the country’s chip knowledge.

The bureau said it raided 10 Chinese companies or their R&D centers which operate in Taiwan without approval earlier this week. In a coordinated crackdown in several cities, the bureau stated that almost 70 people were called for questioning. This included the capital Taipei as well as Hsinchu, the island’s leading semiconductor center.

The bureau released a statement saying that the illegal poaching by Chinese companies of Taiwan’s top-tech talent has adversely affected our international competitiveness as well as endangered our national security.

The government stated that technology was vital for Taiwan’s security, and advised people to be alert to any Chinese activity.

The Bureau did not identify the businesses under investigation, but it added that these companies included electronic parts and design firms for integrated circuits.

Reuters has yet to receive comment from China’s Taiwan Affairs Office on this issue.

According to a top bureau official, the Investigation Bureau launched an investigation into 100 Chinese firms suspected of poaching tech talent illegally.

China has been awash in chip engineering talent, especially in light of Beijing’s ambition to become self-reliant in advanced chips. This is particularly true after Trump’s trade war.

Taiwanese law bans Chinese investment in certain parts of the semiconductor supply chains, such as the design and packaging areas. This makes it difficult for Chinese companies to legally operate on Taiwan.

Eight Chinese businesses were raided by the Bureau in March to counter what they called “the Chinese Communist Party’s illegal activities, talent-poaching, and secret-stealing”.