Investing.com-- In a swift response to new U.S. tariffs, China announced on Tuesday that it has started an antitrust investigation into Alphabet (NASDAQ: GOOGL )'s Google (NASDAQ: GOOG ) and added U.S. companies PVH Corp (NYSE: PVH ) and Illumina Inc (NASDAQ: ILMN ) to its "unreliable entities" list.

Shares in PVH and Illumina slid around 4% each in premarket trading.

The State Administration for Market Regulation stated that the probe into Google will examine alleged monopolistic practices that may have hindered competition in the Chinese market.

Concurrently, Chinese authorities added PVH Corp, the parent company of Calvin Klein and Tommy Hilfiger, and biotechnology firm Illumina Inc to its unreliable entities list, citing actions that harm China's national security.

These measures were announced shortly after President Donald Trump's 10% tariff on Chinese imports was implemented, escalating trade tensions between the world's two largest economies.

Ayushman Ojha contributed to this report.