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.

The Chinese government’s move to open an antitrust probe into Google is the latest development in a long and tangled relationship that goes back to the early 2000s. The investigation was one of a flurry of Chinese retaliatory measures announced Tuesday in response to a 10 percent tariff imposed by U.S. President Donald Trump on imports from China.

China said it had started an antitrust investigation of Google, which works with Chinese companies on smartphones and advertising outside the country.