Philippine government authorities denied entry to a ship suspected of carrying a large volume of illegal drugs near Mindoro Island on Sunday, officials said Wednesday.

The Philippine Coast Guard (PCG) and Philippine Drug Enforcement Agency (PDEA) conducted the joint operation in rough seas just outside the country’s exclusive economic zone near Mindoro.

“Amid heavy weather and rough seas, the joint PCG-PDEA operatives ensured the denial of entry of the subject vessel within the Philippine territory,” PCG said in a statement.

PCG did not name the marine vessel nor reveal the owner and the ship’s country of origin.

PCG Commandant Admiral Ronnie Gil Gavan credited international cooperation and inter-agency collaboration for the operation’s success.

“The success of this operation showed the effectiveness of the national government’s anti-illegal drugs campaign and law enforcement operations within our maritime jurisdiction to prevent the proliferation of illegal drugs in the country,” Gavan said.

PCG declined to provide additional details, citing “operational security.”

The incident echoed several similar maritime drug interdiction efforts in Philippine waters in the past.

In October 2023, authorities seized nearly 1 ton of methamphetamine, locally known as shabu, worth P7 billion from a foreign vessel in waters off the western Philippines.

In 2018, PCG and PDEA intercepted a Taiwanese vessel carrying illegal drugs off the coast of Batanes province, resulting in the seizure of 1,306 pounds of crystal methamphetamine.

The Philippines, which has over 7,600 islands and more than 36,000 kilometers of coastline, has long struggled with maritime drug trafficking due to its porous borders, according to international media reports.