MANILA - The chief of the Philippine Navy said Monday he wants a diplomatic protest filed against China after two Chinese vessels were spotted surveying Recto Bank (Reed Bank), which is about 80 miles off Palawan.

Navy Vice Admiral Giovanni Carlo Bacordo told an online forum that the surveillance ships were initially monitored about a week ago. One of them is still in the area.

"We have reported this already and we have checked if they have any clearance to conduct survey in that area and We found out there is none," Bacordo said.

He emphasized that the ships were conducting surveys because of their slow movement.

"We would like to conclude that indeed they're conducting surveys because they have been there for about a week already, and the speed is something less than three knots, and you're only doing that if you're conducting actual surveys," said Bacordo.

"We will be submitting this report to the defense department and request for the filing of a diplomatic protest."

Bacordo said they have observed “continued presence of Chinese Navy ships, Coast Guard vessels, maritime militia boats, and fishing vessels” as they “continue to patrol the exclusive economic zone in the West Philippine Sea areas, only in the areas which concern us.”

“When they leave,” Bacordo said, “newer vessels take over. It’s like a guard. You are relieved of your duties, another one takes over.”

He said Chinese ships "are closely watching us, but they are not intervening,” adding that there have been fewer vessels ever since the US declared that all of China’s claims in the West Philippine Sea are illegal.

Both the US and China’s military activities have increased in the disputed waters in the past month.