The Philippine Coast Guard on Sunday said it will carry out a maritime patrol to challenge and document the illegal presence of Chinese Maritime Militia vessels in Julian Felipe Reef, a low-tide elevation within the Philippines' territorial waters.

The PCG's action comes in response to a directive from National Security Adviser and Chair of the National Task Force on the West Philippine Sea (NTF-WPS), General Eduardo Año, to address the alarming increase in the number of CMM vessels in the West Philippine Sea.

In a statement posted on X (formerly Twitter), PCG spokesperson to the West Philippine Sea Commodore Jay Tarriela said the agency noted an increase in surveillance of "over 135" suspected Chinese maritime militia vessels (CMM) at Julian Felipe Reef, which marks a significant rise from the preceding month.

Tarriela said the information stemmed from the findings of BRP Sindangan and BRP Cabra, which carried out patrols in the close proximity of the low-tide elevation on Saturday.

"No response was made to the radio challenges issued by the PCG to the CMM vessels which is now estimated to have grown to more than 135 vessels dispersed and scattered within Julian Felipe Reef," Tarriela said.

Julian Felipe Reef is located approximately 175 nautical miles west of Bataraza, Palawan.

It's classified as a low-tide elevation within the territorial sea of important high-tide features in the Kalayaan Island Group, such as Chigua Reef. These areas fall under the sovereignty of the Republic of the Philippines.

"The PCG maintains its unwavering commitment to safeguarding maritime security, safety and the marine environment in the course of protecting the territorial integrity, sovereignty, sovereign rights, and jurisdiction of the Philippines in the West Philippine Sea (by) international laws including the United Nations Convention on the Law of the Sea, the 2016 Arbitral Award and Philippine domestic laws," Tarriela said.

The Philippines secured a significant legal victory in 2016 when an international tribunal ruled in its favor, invalidating China's expansive claims in the South China Sea and affirming Philippine ownership over the West Philippine Sea.

Despite this ruling, China has consistently refused to acknowledge it. Recently, there have been reports of over 50 Chinese vessels near Iroquois Reef and Sabina Shoal, as noted by the Western Command in September.

President Ferdinand "Bongbong" Marcos Jr. stated last November that he urged Chinese officials to abide by international law, specifically the United Nations Convention on the Law of the Sea, in relation to South China Sea areas.

In January, Marcos mentioned that China assured no hindrance to Filipino fishermen despite tensions in the West Philippine Sea, referencing an agreement between Manila and Beijing.

However, tensions persisted in March when China reiterated its claim of sovereign rights over Scarborough Shoal, despite reports from the Philippine Coast Guard about a 'close distance maneuvering' incident involving a Chinese vessel in that area.