China's largest-ever military exercises encircling Taiwan kicked off Thursday, in a show of force straddling vital international shipping lanes after a visit to the island by US House Speaker Nancy Pelosi.
Pelosi left Taiwan Wednesday after a trip that defied a series of stark threats from Beijing, which views the self-ruled island as its territory.
Pelosi was the highest-profile elected US official to visit Taiwan in 25 years, and said her trip made it "unequivocally clear" that the United States would not abandon a democratic ally.
It sparked a furious reaction from Beijing, which vowed "punishment" and announced military drills in the seas around Taiwan -- some of the world's busiest waterways.
The exercises, which began around 12 pm (0400 GMT), involve "live-firing", according to state media.
"Six major areas around the island have been selected for this actual combat exercise and during this period, relevant ships and aircraft should not enter the relevant waters and airspaces," state broadcaster CCTV reported.
The exercises will take place in multiple zones around Taiwan -- at some points within just 20 kilometers of the shore -- and will conclude at midday on Sunday, AFP reported.
Taiwan's defense ministry said it was closely watching the drills.
"The Ministry of National Defense stresses that it will uphold the principle of preparing for war without seeking war, and with an attitude of not escalating conflict and causing disputes," it said in a statement.
Beijing's nationalist state-run tabloid Global Times said, citing military analysts, that the exercises were "unprecedented" and that missiles would fly over Taiwan for the first time.
"This is the first time the PLA will launch live long-range artillery across" the Taiwan Strait, the newspaper said using the Chinese military's formal name, the People's Liberation Army.
The Group of Seven industrialized nations has condemned the drills, saying in a statement there was "no justification to use a visit as pretext for aggressive military activity in the Taiwan Strait".
Taiwan's Maritime and Port Bureau issued warnings on Wednesday to ships to avoid the areas being used for the Chinese drills.
The Taiwanese cabinet said the drills would disrupt 18 international routes passing through its flight information region (FIR).
Hong Kong carrier Cathay Pacific said it had ordered its aircraft to "avoid going through the designated airspace zones around the Taiwan region".
The maneuvers will take place along some of the busiest shipping routes on the planet, used to supply vital semiconductors and electronic equipment produced in East Asian factory hubs to global markets.
Beijing has defended the drills as "necessary and just", pinning the blame for the escalation on the United States and its allies.
"In the current struggle surrounding Pelosi's Taiwan visit, the United States are the provocateurs, China is the victim," foreign ministry spokeswoman Hua Chunying told a regular briefing Wednesday.
A Chinese military source also told AFP the exercises would be staged "in preparation for actual combat".
"If the Taiwanese forces come into contact with the PLA on purpose and accidentally fire a gun, the PLA will take stern countermeasures, and all the consequences will be borne by the Taiwanese side," the source said.
Taiwan's 23 million people have long lived with the possibility of an invasion, but that threat has intensified under President Xi Jinping, China's most assertive ruler in a generation.
The island is once again a flashpoint between the United States and a Chinese leadership keen to project strength ahead of a crucial ruling party meeting this autumn at which Xi is expected to be given an unprecedented third term.
On the mainland, at what is said to be China's closest point to Taiwan, AFP saw a batch of five military helicopters flying at a relatively low altitude near a popular tourist spot.
"China's announced military exercises represent a clear escalation from the existing baseline of Chinese military activities around Taiwan and from the last Taiwan Strait Crisis in 1995-1996," said Amanda Hsiao, senior analyst for China at the International Crisis Group.
"Beijing is signaling that it rejects Taiwan's sovereignty."
Nevertheless, analysts have told AFP that China is not aiming to escalate the situation beyond its control -- at least for now.
Titus Chen, an associate professor of political science at the National Sun Yat-Sen University in Taiwan, said: "The last thing Xi wants is an accidental war."