China begins its biggest military exercises in the seas around Taiwan after the visit of American politician Nancy Pelosi, the BBC informed.

The exercise began at 12:00 local time (04:00 GMT) and was to take place within 12 miles of the island in several areas.

Taiwan has said that China is trying to change the status quo in the region.

Nancy Pelosi made a brief but controversial visit to Taiwan, which China considers a breakaway province.

The exercises are Beijing's main response, although it has also blocked trade with the island.

The drills are to be held in busy waterways and will involve firing long-range live rounds, Beijing said.

According to Taiwan, this amounts to a sea and air blockade.

The US said that the exercises were irresponsible and could get out of control.

Analyst Bonnie Lin told the BBC that Taiwan's military would react cautiously, but there was still a risk of confrontation.

Taiwan said it sent planes to warn off Chinese warplanes on Wednesday, and its military fired missiles to drive off unidentified aircraft over the Kinmen Islands, located near the mainland.

27 Chinese warplanes entered Taiwan's air defense zone

Several ministries have suffered cyberattacks in recent days, the Taiwanese government said.

Taiwan has also requested that the ships take different routes and is negotiating with Japan and the Philippines to find alternative aviation routes.

The declaration of six large no-go zones around the island is ominous.

Beijing did the same in 1996, when it last had the so-called "Taiwan Strait Crisis".

But then all the restricted areas were well outside Taiwan's territorial waters.

This time, three of the six zones fall within Taiwan's 12-mile limit.

This is unprecedented.

Taiwan's defense ministry has already called the move a violation of UN conventions and said it amounts to an air and sea blockade against the island.

If China moves ships or aircraft into these areas, it will be tantamount to invading Taiwan's territory.

This makes the stakes much higher, as Taiwan may feel compelled to defend its own waters.

The US Navy is watching all of this very closely and already has the USS Ronald Reagan carrier battle group sailing nearby in the Philippine Sea.

Japan has also raised concerns with China over the areas covered by the military exercises, which it says overlap with its exclusive economic zone.

military exercises