The Philippines is accusing China of sending more government ships and fishing boats to a disputed shoal in the South China Sea, in a move Manila says is escalating a two-month long standoff.

Philippine Foreign Affairs spokesperson Raul Hernandez said Wednesday there are nearly 100 Chinese vessels at the Scarborough Shoal. He said some were observed fishing, despite a recently announced fishing ban by both countries.

“It is regrettable that these actions occurred at a time when China has been articulating for a de-escalation of tensions, and while the two sides have been discussing how to diffuse the situation in the area.”

Hernandez called for China to immediately withdraw the vessels, saying Manila has lodged an official protest with the Chinese embassy over the build-up. He said talks are ongoing to resolve the dispute.

China and the Philippines both imposed separate temporary fishing bans in the area a week ago, in an attempt to de-escalate tensions over the shoal, which both countries claim as sovereign territory.

Both countries have had boats stationed near the shoal since early April, when a Chinese vessel prevented a Philippine Navy ship from arresting a group of Chinese fishermen.

China says the islands, known as Huangyan in China, are a key part of Chinese territory and that any Philippine claim to them is baseless. The Philippines says the shoal is within its internationally recognized exclusive economic zone.

China has already rejected a request by the Philippines to refer the issue to an international court.

The standoff is part of a wider territorial dispute in the South China Sea, parts of which are also claimed by Vietnam, Taiwan, Malaysia, and Brunei. China claims nearly the entire region, which is thought to contain large amounts of oil and natural gas.