China announced a ban on Tuesday on imports of genetic sequencers from U.S. medical equipment maker Illumina, just minutes after U.S. President Donald Trump’s additional 10% tariff on Chinese goods took effect.

The ban is part of a series of measures China announced in response to the extra U.S. tariffs and comes after Beijing put Illumina on its “unreliable entity” list in February.

China accounts for about 7% of Illumina’s sales.

China’s commerce ministry said in a statement that Illumina “violated the principle of normal market transactions, suspended normal transactions with Chinese enterprises and took discriminatory measures against Chinese enterprises, seriously harming the interest of Chinese enterprises.

“Taking into account the circumstances of the company’s violation of the law and other factors, the working mechanism of the Unreliability List in accordance with the law made a decision to prohibit it from exporting gene sequencers to China,” it said.

Gene sequences help determine the sequence of DNA or RNA to study genetic variations associated with diseases and diagnose rare genetic conditions.

Illumina did not immediately reply to a request for comment.