Besides Wednesday's live-fire naval drill in the Taiwan Strait, the PLA has been flying fighter jets and bombers close to the self-ruled island - possible signs of a coordinated battle plan, say experts

Recent patrols by China's air force in and around Taiwan appear to be part of a coordinated strike plan across different branches of Chinese military that will encompass the entire area - possibly as preparation for military conflict with the self-ruled island - experts have said.

The air force conducted several “island encirclement” patrols in and around Taiwan in recent days, the People's Liberation Army said on Thursday - one day after the mainland's navy carried out a live-fire drill in the Taiwan Strait.

Song Zhongping, a former member of the PLA's Second Artillery Corps, said that although the live-fire drill appeared smaller than expected, that was probably down to the fact that it was part of a wider mission.

“It seems like the exercise near Fujian was relatively small, but actually, there were several joint operational drills happening in different areas around Taiwan at the same time [on Wednesday],” he said.

“The comprehensive, joint operational drills suggest the PLA is not just targeting one area, but the whole region.”

Tension has been high between China and Taiwan since Taiwanese President Tsai Ing-wen - whose Democratic Progressive Party advocates for independence from China - was elected president in 2016.

China has said that if Taiwan attempts to declare independence, it will view that as grounds for military intervention to take the island back.

The PLA said various aircraft, including H-6K bombers, Su-30 and J-11 fighters, spy jets, early-warning planes and others, had taken part in the island encirclement patrols.

Taiwan's defence ministry said it spotted two H-6K bombers flying over the Miyako Strait in Japan, and through the Bashi Channel, between Taiwan and Philippines, en route to the Western Pacific. Both Taiwan and Tokyo said they scrambled aircraft and warships to monitor the activity.

On Wednesday, the PLA's ground force said it had sent an aviation unit to take part in the 15-hour live-fire drill off the coast of southwestern China's Fujian province. It described the day and night drills as “routine” to test the forces' all-weather combat capabilities.

China's military newspaper PLA Daily said that Z-9 and Z-19 helicopters were used to simulate missile attacks on warships.

Song, who is now a military commentator on Phoenix Television, said the PLA appeared to be building a “comprehensive plan” to resolve the Taiwan issue, in which a battle group led by the Liaoning aircraft carrier — which conducted its first systematic drills after taking part in a massive naval parade off the coast of Hainan province last week — was likely to play a key role.

“The ground force's aviation drills in Fujian, the air force's flying over the ‘first island chain' and the Liaoning full-voyage exercises all indicate that the PLA has a comprehensive battle plan for Taiwan,” he said.

The “first island chain” is a series of archipelagoes lying between China and the Western Pacific, which Beijing says has been used by the United States as a natural barrier to contain it since the cold war.

Another military expert, who asked not to be named, said the latest drills were undoubtedly part of the PLA's preparations should it ever decide to try to take back Taiwan by force.

Beijing said earlier that the purpose of the live-fire drill in the Taiwan Strait was to deter separatists on the island. But to the people living on the Taipei-controlled island Quemoy, which lies about 60km (37 miles) from the drill site, the military presence was nothing new.

“People are used to hearing the roar of the guns, it's been going on for decades,” said Cindy Lin, who runs a travel agency on Quemoy. “Ninety per cent of people here believe Beijing just wants to frighten the Taiwanese people, but won't actually hurt us.”