China launched military drills around Taiwan on Saturday as a “serious warning” to separatist forces in an angry but widely expected response to Vice-President William Lai’s visit to the US, drawing condemnation from Taipei.

Lai, the front-runner to become Taiwan’s President in elections in January, returned from the US on Friday. He officially made only stopovers on his way to and from Paraguay but gave speeches while in the US.

China views democratically governed Taiwan as its own territory, despite the strong objections of the island’s government.

The People’s Liberation Army’s Eastern Theatre Command, which has responsibility for the area around Taiwan, said in a brief statement it was carrying out joint naval and air combat readiness patrols around the island.

Taiwan’s defence ministry said it had detected 42 Chinese aircraft and eight ships involved in drills around the island from Saturday morning and that it had deployed ships and aircraft in response.

Twenty-six Chinese aircraft crossed the median line of the 100km wide Taiwan Strait, or areas beyond each end of the line, the ministry said in a statement.