National Police chief Ronald dela Rosa said police and drug enforcement agents seized the methamphetamine hydrochloride, known locally as shabu, in 180 plastic bags on Sunday in an abandoned farm in northern Cagayan province's Claveria town following a tip from an informant.
Authorities are investigating whether it was smuggled into the Philippines by a foreign syndicate or was manufactured locally, officials said.
He also said more than 100 armed drug dealers have been killed in gunbattles with police since last month and thousands of drug users have surrendered to authorities during the intensified anti-drug campaign. The drug users will undergo mandatory drug treatment.
Nine policemen from different regional offices who tested positive for illegal drugs in mandatory tests last Friday will face criminal and administrative charges, he added.