China is again carrying out military exercises in the contested South China Sea, as the US steps up reconnaissance amid rising tensions in the region.

The People's Liberation Army is conducting at least three live-fire drills starting from Wednesday in waters to the east and south of Hainan Island and in the Beibu Gulf, known as the Gulf of Tonkin in Vietnam, according to notices issued by the local maritime safety authorities.

The exercises follow live-fire drills in the South China Sea last week that ran for "several days", military mouthpiece PLA Daily reported on Sunday. It said the drills by the PLA South Sea Fleet included main gun firing, mine hunting, helicopter operations and rescue missions.

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A day before this week's scheduled PLA exercises, the US Air Force sent an RC-135W spy plane over the no-entry zones marked out by Chinese maritime safety authorities, according to the South China Sea Strategic Situation Probing Initiative (SCSPI), a Beijing-based think tank that monitors military activity in the region.

On Tuesday, the reconnaissance aircraft left the US military base in Okinawa and flew near the Guangdong coastline and Hainan Island on a patrol that "highly matched" the locations of the planned PLA drills, the SCSPI said.

American spy planes carried out a record 94 sorties over the South China Sea near the Chinese coast in November, according to data compiled by the SCSPI.

Beijing's expansive claims to most of the South China Sea overlap with those of Vietnam, the Philippines, Malaysia, Brunei and Taiwan. China has rejected an international tribunal ruling that it has no legal basis for its claims.

Tensions have been rising in the region as China rapidly expands its navy and has set up military outposts on artificial islands in the resource-rich sea, one of the world's busiest waterways. The US has responded by increasing its military presence in the region, conducting regular "freedom of navigation operations" near Chinese-controlled islands to challenge its claims, as well as flyovers and more surveillance missions. Other Western nations have also increased their military presence in the region.

PLA drills may turn into full-scale attack, Taiwan army warns

According to a military source close the PLA, China's latest live-fire drills were supposed to be held earlier in the year but were postponed because of the coronavirus pandemic and frequent visits to the region by American aircraft and warships.

The PLA South Sea Fleet is based in the southern province of Guangdong, where the Delta variant first emerged in mainland China in May. Personnel from the fleet were caught up in quarantine and other pandemic restrictions amid outbreaks of the highly infectious strain, according to the source, who requested anonymity because of the sensitivity of the matter.

"So they need to catch up and complete their targets by the end of the year," he said.

Additional reporting by Minnie Chan

Copyright (c) 2021. South China Morning Post Publishers Ltd. All rights reserved.

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