MANILA - The Philippines has filed a diplomatic protest over the ship-ramming incident in the West Philippine Sea, Foreign Affairs Sec. Teodoro "Teddy" Locsin said Thursday.

Locsin issued the statement on his Twitter account a day after Defense chief Delfin Lorenzana said a Chinese vessel rammed and sunk a Filipino fishing boat, and abandoned 22 fishermen in open waters.

"I fired off a diplomatic protest yesterday," Locsin said in a tweet in response to Sen. Antonio Trillanes IV's recommendation to take the issue to an international agency.

"I will proceed on the merits of the case and what it calls for while the matter is studied by the International Maritime Organization (IMO)," he added.

Locsin earlier described the "hit and run" incident as "contemptible and condemnable."

• Foreign affairs chief on Chinese vessel collision: Contemptible, condemnable

The Philippine ship was anchored when it was hit by the Chinese vessel, Lorenzana said.

A Vietnamese fishing vessel in the area rescued the Filipino fishermen in coordination with the Philippine military.

The Armed Forces' Western Command said the incident was "far from accidental" and likened it to a "hit and run."

"After the collision, the Chinese vessel immediately umalis, tumakas, parang hit and run (immediately left, it was like a hit and run)," AFP Wescom spokesman Lt. Col. Stephen Penetrante said.

Presidential spokesperson Salvador Panelo said Manila would ask Beijing to sanction the crew of the Chinese ship involved in the incident.

• Philippines asks China to sanction ship crew in 'hit-and-run'

The Philippines and China have long been involved in a maritime dispute as Beijing continues to assert its sweeping claims over the South China Sea.

In the past months, sightings of Chinese vessels in Philippine waters have made headlines amid rising tensions.

The Philippine military had said it monitored more than 600 Chinese ships near Pag-asa Island since January of this year.