US reconnaissance in the South China Sea continues to operate, apparently conducting a submarine discovery operation in China.

"The US EP-3E reconnaissance aircraft, coded AE1D91, entered the South China Sea through the Strait of Poland on the afternoon of June 26. P-8A maritime patrol aircraft and KC-135 refueling aircraft clung right behind," the organization said.

The image published by SCSPI shows three US aircraft crossing the Air Defense Identification Area (ADIZ) in southwestern Taiwan, then flying toward the South China Sea.

Taiwan's defense agency did not comment on the flight routes of the three aircraft, only insisting that it was aware of all foreign military operations around the island of Taiwan and was on duty to ensure the island's safety.

However, an unnamed security source in Taipei said that the US Air Force is most likely conducting a joint hunting mission in the area.

"US military aircraft are constantly present in the Ba Si Strait and the northern part of the South China Sea, showing that the Pentagon has intelligence on the operation of Chinese submarines here. The presence of many aircraft.

Su Tzu-yun, an expert at the Taiwan Institute for Defense and Security Studies (INDSR), said the US military might be acting on specific intelligence.

"If China deploys submarines through the Strait of Ba Si and Balintang, between Taiwan and the Philippines, they will deter US naval operations between the South China Sea and the Philippine Sea. Such deployment shows intention.

Ba Si Strait (highlighted in red).

Tensions in the Taiwan Strait have recently increased as mainland China has conducted nine fighter jets, bombers, and mechanical muscle transport against the island in June.

Experts say the flights close to Taiwan seem to be a reaction of Beijing after Washington let air transport fly over the western edge of the island, and deterred Taipei from launching two missiles on June 11.