New installations have appeared on Yagong Island near Antelope Reef in the disputed South China Sea, as China continues to expand its presence in the region. Satellite images reviewed by Reuters show a three-pronged construction on the small islet. Security analysts believe the new structures could eventually support military facilities developed at nearby Antelope Reef.

Vantor, a commercial satellite imagery provider, captured the latest image of Yagong Island on August 17. Other images reviewed by the company indicate that construction began in March and April. The exact purpose of the new structures remains unclear. However, their design has raised concerns among regional security experts.

A Vantor spokesperson said, "Several structures on Yagong Reef resemble other military radar/early warning facilities seen elsewhere in the South China Sea and are likely associated with the ultimate military functions of nearby Antelope Reef". The company said it was still too early to determine the precise role of the installations.

Analysts have suggested that the new construction could be the beginning of an early warning radar facility. Such a facility could support future military infrastructure on Antelope Reef. Open-source intelligence tracker Damien Symon, who has closely followed developments in the Paracels, said a radar facility was possible. He added that it was still too early to make a firm assessment.

Singapore-based security scholar Collin Koh also pointed to a possible military role. He said the limited size of the installation could indicate a standalone observation post. However, he added that it was "most likely a radar station, if I can make an educated guess".

The developments come after Reuters reported last week that China had completed the first phase of construction at Antelope Reef. The activity has further highlighted the growing militarisation of the South China Sea. The waterway is already a major point of tension between China, the United States and its allies. It could also become strategically important in any future conflict involving Taiwan.

Satellite images of Antelope Reef show a large artificial island that stretches for nearly 6 km (4 miles). It has a straight coastline extending for more than 3 km (2 miles). Some analysts believe the straight section could eventually serve as a runway. The scale of the construction has raised concerns over China's long-term military plans in the region.

Yagong Island is much smaller than Antelope Reef and lies about 14 km to its northeast. Both locations are part of the Crescent Group in the western Paracels. Their proximity could allow facilities on Yagong to support operations and surveillance linked to the larger development at Antelope Reef.

China's defence ministry did not immediately respond to Reuters' requests for comment. Beijing has also not publicly acknowledged that it is building a new military base at Antelope Reef. Chinese state media have instead said the development will serve civilian purposes. These include weather forecasting, fisheries protection and scientific research.

China has controlled the Paracel Islands since 1974. It seized the islands from the navy of the former South Vietnam that year. Vietnam continues to claim the entire island group. In recent years, Hanoi has also expanded its own network of bases in the Spratly Islands, located farther south.

The wider Spratly Islands and surrounding waters are subject to overlapping claims from Vietnam, the Philippines, Malaysia, Taiwan and Brunei. The competing claims have made the South China Sea one of Asia's most sensitive security flashpoints. The Vietnamese foreign ministry did not immediately respond to Reuters' request for comment.

Regional security analysts and military attachés say the growing construction is more likely to strengthen China's military control over the northern section of the strategically important waterway. The latest activity on Yagong Island could therefore form part of a broader effort to expand surveillance and defence capabilities around Antelope Reef.

The exact purpose of the new installations remains uncertain. Still, their appearance adds to growing evidence of China's expanding infrastructure across the Paracels. If the structures become part of a radar or early warning network, they could give China greater ability to monitor activity across the northern South China Sea.