MANILA (Reuters) - Philippine anti-narcotics agents raided an illicit drug laboratory on Thursday and arrested four Chinese nationals and four Filipinos, acting on what the drug enforcement agency said was a tip from their Chinese counterparts.

The suspects were arrested in three separate locations after agents took control of an illegal laboratory that was capable of producing 25 kgs of methamphetamine daily, said Aaron Aquino, head of the Philippine Drugs Enforcement Agency (PDEA).

It came two days after Chinese President Xi Jinping met Philippine counterpart Rodrigo Duterte in China’s Hainan province and pledged support for his ferocious war on drugs, which has killed more than 4,000 people in the last 20 months.

Aquino said China’s National Narcotics Control Commission had been monitoring “drug chemists” flying in and out of the country since October 2017. The laboratory raid and arrests were in the provinces of Batangas and Cavite.

“I would like to express our gratitude to our Chinese counterparts for their intelligence support and cooperation,” Aquino told reporters, adding anti-narcotics agents also seized large amount of chemicals and precursors used for making the illegal drugs.

Aquino said two of the four Chinese “cooks” were arrested at a poultry farm with three Filipinos early on Thursday morning and another Chinese chemist was caught with his Filipino driver in a nearby city.

The fourth Chinese national was arrested hours later in his rented home in Tagaytay, a mountain resort city south of Manila.

PDEA has dismantled nine drug laboratories since July 2016, confiscating nearly 20 billion pesos ($384.3 million) in precursors, chemicals, and laboratory equipment, said the agency’s spokesman, Derrick Carreon.

More than 123,000 people had been arrested in about 90,000 anti-drug operations nationwide since then, he added, disputing activists’ allegations that law enforcement agencies were intentionally killing suspects.