China said it was opening an antitrust probe into Google, part of a series of actions Tuesday that also included tariffs on U.S. coal and liquefied natural gas imports as well as restrictions on the export of certain metals.

China has announced a flurry of retaliatory measures against the U.S., including tariffs on imports of products such as coal, liquefied natural gas products and crude oil, as well as an antitrust probe into Google.

China's antitrust investigation into Google, which does not offer most of its consumer-facing services including search and email in the country, seems to make little sense on the surface, but analysts said the move could be seen as a warning shot to the US and a threat to the Android operating system.