Hong Kong (CNN) A United States Navy warship conducted a "freedom of navigation operation" Wednesday aimed in part at challenging China's claims in the South China Sea, the second such operation in as many days near disputed islands that the US has accused Beijing of militarizing.

The operations come amid heightened tension between Washington and Beijing over the handling of the coronavirus and after US Secretary of State Mike Pompeo accused China of exploiting attention given the pandemic to "bully" its neighbors in the South China Sea (SCS).

The guided-missile cruiser USS Bunker Hill on Wednesday "asserted navigational rights and freedoms in the Spratly Islands, consistent with international law," said Cmdr. Reann Mommsen, a spokesperson for the Navy's 7th Fleet, in a statement.

The Spratlys, called the Nansha Islands by China, are in the southern portion of the 1.3 million square mile South China Sea. While several countries have claims on the island chain, the US has long accused China of militarizing the Spratly Islands by deploying anti-ship cruise missiles and long-range surface-to-air missiles to Chinese outposts there.

"This freedom of navigation operation upheld the rights, freedoms, and lawful uses of the sea recognized in international law by challenging the restrictions on innocent passage imposed by China, Vietnam, and Taiwan," Mommsen said.

Read More