Chinese construction work on a runway at Antelope Reef in the disputed Paracel Islands is gathering pace, according to commercial satellite imagery reviewed by Reuters, adding a new point of focus to an already militarised stretch of the South China Sea.

The images, taken on 25 September by commercial provider Vantor, showed grading work, piles of gravel and concrete, compaction cranes and a fully loaded gravel barge approaching a newly built wharf, Reuters reported. Analysts told the agency that the work was consistent with the construction of a full-scale runway.

Ben Lewis of the open-source platform PLATracker estimated that, if construction followed the model of China’s earlier runway-building at Fiery Cross Reef, paving could be completed in the first half of 2027 and a first landing could follow by mid-year. That is an analyst estimate, not a Chinese construction timetable.

Antelope Reef lies in the Paracels, a group of features occupied by China and also claimed by Vietnam and Taiwan. The location matters because a completed base could expand the reach and endurance of Chinese naval and air operations in the northern South China Sea, close to the approaches to Hainan Island.

China’s defence ministry did not immediately respond to Reuters’ request for comment. Chinese state media have described Antelope as a site for civilian functions including weather forecasting, maritime work and scientific research. Beijing has not publicly acknowledged construction of a new military base there.

The satellite evidence is significant precisely because it shows physical progress, but it cannot alone establish every future use of the site. The defensible conclusion is narrower: a substantial runway project appears to be under way at a contested feature, and outside analysts believe it could become operational in 2027.