The Philippines is monitoring the world’s largest coast guard vessel, the 165-meter-long Chinese Coast Guard Ship 5901, nicknamed “Monster,” which is occupying a disputed point in the South China Sea, in what analysts see as a show of force to back up Beijing’s sweeping claims.

Speaking to the Philippine News Agency on Tuesday, Rear Admiral Roy Vincent Trinidad, a spokesman for the Philippine Navy, said the Monster was dispatched in response to the longer-than-usual presence of a Philippine Coast Guard vessel near the shoal.

Located about 700 miles from the nearest Chinese coast and less than 150 miles from the Philippine province of Palawan, the Sabina Reef of the Spratly Islands lies right in the middle of the Philippines’ internationally recognized exclusive economic zone (EEZ). International maritime law grants states exclusive rights to natural resources within their EEZ.

Beijing’s claims to the South China Sea overlap with those of neighboring countries such as the Philippines, Vietnam, Malaysia, Brunei, Indonesia and Taiwan.

The Philippine ship observed the unusual collection of crushed coral, Trinidad said. He added that there was no standoff between the two vessels. “So, they’re watching them; they’re watching us,” he said.

The Philippine Navy and the Chinese Foreign Ministry did not immediately respond to written requests from Newsweek for a comment.

Ray Powell, director of the Stanford University-affiliated SeaLight Initiative, said Newsweek This ship-tracking data showed that the “monster” had been in the Sabina Reef since July 3. “Although its automatic information system (AIS) transmissions were ‘turned off’ on July 31, aerial photographs showed it was still there, a visible symbol of China’s claim of sovereignty over this sea surface,” Powell added.

To ensure the safety of shipping, the UN has required ships to continuously transmit their positions via AIS.

Powell predicted the ship would soon head to China, as the country’s coast guard vessels typically deploy for a month and a half at a time. “If that’s the case, it will probably be replaced by another large ship, obviously not as big as the monster, as it’s the largest in the world,” Powell said.

In June, the ship also entered the EEZ of two other South China Sea countries, Malaysia and Brunei, according to the Philippine Coast Guard, which said it had detected the “monster’s” movements using dark vessel detection technology used by Canada.

Resistance from the US ally under President Ferdinand Marcos Jr. has led to increasingly forceful reactions from China. A clash last month left several Filipino soldiers injured, raising the risk of a breach of the mutual defence pact between Manila and the US.

Beijing insists that Manila is stirring up unrest in the region on behalf of its US ally and that this is part of Washington’s efforts to contain China.

“China’s claims to territorial sovereignty and maritime rights and interests in the South China Sea are in line with international law and universal practice,” Mao Ning, spokesman for the Chinese Foreign Ministry, told reporters on Tuesday. “It is the Philippines, not China, that is causing problems in the South China Sea.”