SHANGHAI, March 4 (Reuters) - China announced a ban on

Tuesday on imports of genetic sequencers from U.S. medical

equipment maker Illumina ( ILMN ), 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 ( ILMN ) on its "unreliable entity" list in February.

China accounts for about 7% of Illumina's ( ILMN ) sales.

China's commerce ministry said in a statement that Illumina ( ILMN )

"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 ( ILMN ) did not immediately reply to a request for comment.