BEIJING (PTI):  China has started building the country's most-advanced large unmanned ship even as it geared up to launch its third aircraft carrier which was delayed by the prolonged COVID-19 outbreak in Shanghai.

Led by the Research Institute of the China State Shipbuilding Corporation Limited (CSSC), a ceremony was held to celebrate the start of the large unmanned ship project, state-run Global Times reported.

This means that the ship, being the most-advanced of its kind in China, has officially entered the construction phase, the report said on Thursday.

Featuring a high-speed hydrofoil trimaran design, the drone ship is characterised by its high speed, long endurance and fully domestically-developed propulsion system.

In addition, it can independently carry out missions under different scenarios, it said.

Also, China is preparing to launch its third aircraft carrier.

It was due to be launched on April 23, the People's Liberation Army Navy (PLAN) Day, but was delayed by over two month-long COVID-19 outbreak in Shanghai.

With the resumption of work at the Jiangnan Shipyard in Shanghai, the third aircraft carrier could be launched soon, a Chinese military expert told the Global Times.

China's third aircraft carrier was expected to be larger than the previous two carriers, and it will likely use electromagnetic catapults to replace the previous two carriers' ski-jump ramps to launch aircraft.

Recent reports, however, said that the speedy launch of the aircraft carriers is resulting in technical and repair issues, delaying their operational readiness.

In April, China's indigenously built second aircraft carrier Shandong , which was launched in 2019, had to undergo its first maintenance and comprehensive examination .

A comprehensive examination to the carrier could be carried out and upgrades and overhaul could be made to those parts that encountered problems or can be optimised based on the experiences gained over the past two years, an official media report said earlier.

China's first aircraft carrier, the Liaoning, a refit of the Soviet-era ship which was commissioned in 2012, is so far the only Chinese aircraft carrier with initial operational capability or the basic level of combat readiness.

China launched its first indigenously-built aircraft carrier Shandong in 2019 with plans to build four more.

However, no official reason has been given as to why Shandong has not reached the combat-readiness stage, the Post report said, sparking speculation that the first domestically-built aircraft carrier faced operational problems.

Last month, China launched what was described as the world's first drone aircraft carrier.

The ship can carry 50 unmanned systems, including unmanned boats, drones and underwater vehicles, a video report carried out by the state-run CCTV said.

With the world's first drone mothership, the Chinese military is expected to gather more intelligence in the disputed South China Sea, despite a security analyst assessment finding the ship potentially vulnerable to enemy interference or a technological failure, Hong Kong-based South China Morning Post reported earlier.

The state-run Science and Technology Daily said the ship could be an efficient tool in marine disaster prevention and mitigation, environmental monitoring and offshore wind farm maintenance as well as delivering accurate marine information.

Timothy Heath, a senior security analyst from US think tank Rand, said the drone mothership could definitely be used for military applications.

The drone carrier might be deployed to remote locations to deploy smart mines, for example, he said.

The most immediate benefit to the PLA is the increase in knowledge about relevant waters through the collection of data by the UUVs (unmanned underwater vehicles).

This can help PLA Navy submarines operate with greater confidence and effectiveness in those areas, he told the Post.

However, Heath said that this autonomous ship had the same risk of electronic jamming as all other unmanned vessels.

With no human on board, the vessel in autonomous mode could make bad decisions in the face of unexpected circumstances, resulting in mission failure, he said.

Besides jamming, drones could be spoofed when its communication link is hijacked and control of the vehicle is taken over or destroyed by lasers or other weapons, he said.

China is rapidly modernising its Navy, including the building of new aircraft carriers.

Chinese President Xi Jinping, who heads the military besides the ruling Communist Party of China (CPC), has carried out extensive reforms of the military, including downsizing of the Army and enhancing the role of the Navy and Air Force as Beijing set its sights on the global expansion with military bases in Djibouti in the Horn of Africa.

China has also taken over Sri Lanka's Hambantota port for a 99-year lease and expanded and modernised Pakistan's Gwadar port in the Arabian Sea.

China claims nearly all of the disputed South China Sea, though Taiwan, the Philippines, Brunei, Malaysia and Vietnam all claim parts of it. Beijing has also built artificial islands and military installations in the South China Sea.