More than 30 vessels have transited through China’s drill zone south of Taiwan’s main port since Sunday, according to ship-tracking data compiled by Bloomberg, with the latest ship positions showing four of the total six zones being traversed. 

Shipping in the Taiwan Strait, a key route for supply chains and commodities, has faced uncertainty and delays since Beijing began its most provocative military drills in decades in the wake of House Speaker Nancy Pelosi’s trip to Taiwan last week. Some shipowners barred their vessels from transiting the strait, while others navigated around the drill zones. 

Vessels had also been hesitant about approaching the major port of Kaohsiung in southern Taiwan, seeking to avoid the large drill zone located just offshore. Ships are now starting to resume their original routes. 

The supertanker Barakah, laden with crude oil from the Middle East, was moored off Kaohsiung on Monday after last week diverting to the Sha Lung port at the northern end of the island, according to data compiled by Bloomberg. Crude tanker Ghinah is also en route to Kaohsiung after changing its route to Sha Lung. 

Two liquefied natural gas vessels also arrived at ports in Taiwan on Monday after idling off the coast for a few days, according to the data.

The military exercises were scheduled to be completed on Sunday, but it’s unclear whether the drills have ended. There has been no official announcement, and Hu Xijin, former editor of the Communist Party’s Global Times newspaper, said they had been extended. 

China also publicised drills in other areas along its coast, including live-weapon firing from 6 to 15 August in the southern part of the Yellow Sea separating the mainland from the Korean Peninsula – a frequent area for exercises. 

The Maritime Safety Administration also said military exercises will take place in parts of the Bohai Sea in the north for a month from 8 August, and warned ships to avoid entering the area. Drills were also held in that region around this time last year.

Meanwhile, Reuters reports that China’s defence ministry on Monday defended its shelving of military talks with the United States in protest against House Speaker Nancy Pelosi’s visit to Taipei last week, warning that Washington must bear “serious consequences”.

Pelosi’s visit last week infuriated China, which regards the self-ruled island as its own and responded with test launches of ballistic missiles over Taipei for the first time, as well as ditching some lines of dialogue with Washington.

“The current tense situation in the Taiwan Strait is entirely provoked and created by the US side on its own initiative, and the US side must bear full responsibility and serious consequences for this,” defence ministry spokesman Wu Qian said in an online post.

“The bottom line cannot be broken, and communication requires sincerity,” Wu said.

Four days of unprecedented drills were scheduled to end on Sunday. Chinese authorities have not officially confirmed they have ended, amid fears among some security analysts that the situation in the Taiwan Strait, particularly near the unofficial median line buffer, remains tense.

About 10 warships each from China and Taiwan manoeuvred at close quarters around the line on Sunday, according to a person familiar with the situation who is involved with security planning.

The island’s defence ministry said Chinese military ships, aircraft, and drones had simulated attacks on the island and its navy. It said it had sent aircraft and ships to react “appropriately”.

China called off formal talks involving theatre-level commands, defence policy co-ordination and military maritime consultations on Friday as Pelosi left the region.

Pentagon, State Department and White House officials condemned the move, describing it as an irresponsible overreaction.

China’s cutting of some of its few communication links with the US military raises the risk of an accidental escalation over Taiwan at a critical moment, according to security analysts and diplomats.

One US official noted that Chinese officials had not responded to calls from senior Pentagon officials amid the tensions last week, but that they did not see this as a formal severing of ties with senior figures, such as US Defence Secretary Lloyd Austin.

Asked directly about those reports, defence ministry spokesman Wu said, “China’s relevant countermeasures are a necessary warning to the provocations of the United States and Taiwan, and a legitimate defence of national sovereignty and security”.