MANILA — Magdalo Rep. Gary Alejano on Tuesday said there is a "suspicious" convergence of boats from the Chinese Navy, its coast guard and maritime militias north of Pag-asa Island, which is a threat to Philippine interest in the West Philippine Sea.

Alejano said in a press conference that he received information from his military sources, saying that since 3 days ago China has deployed 2 frigates, a coast guard vessel, and 2 large fishing vessels with their maritime militia about 1 to 3 nautical miles north of Pag-asa Island.

Pag-asa (Thitu), part of the Spratly group of islands, is located about 480 kilometres west of Puerto Princesa City in Palawan.

Alejano added, 2 days ago, Chinese fishing vessels prevented a ship from the Philippines' Bureau of Fisheries and Aquatic Resources from going near the sand bars located west of Pag-asa.

"This is highly suspicious and threatening considering the fact that China says one thing in public and does another on the ground," he said.

"For example, our fishermen continued to be harassed in West Philippine Sea by Chinese Navy or Coast Guard. Let us not forget what happened in 1995 when they grabbed Mischief Reef from us."

Alejano said the government should take the movement seriously, urge China to order its ships to leave Pag-asa, and file an appropriate diplomatic protest against Beijing.

"I call on the Philippine government officials to be transparent in what is happening in West Philippine Sea. We must assert our rights in the midst of talks with China," he said.

Albay Rep. Edcel Lagman asked if there is a portion in the proposed 2018 budget allocating funds for the enforcement of the arbitral ruling won by the Philippines against China.

This as Lagman reiterated that plans for a joint exploration with China in the disputed waters are unconstitutional.