Two police officers in the Philippines were killed in a shootout with other federal agents during a botched undercover drug bust, according to official state media Philippine News Agency (PNA).

The two officers, from the Philippine National Police (PNP), faced off against agents from the Philippine Drug Enforcement Agency (PDEA) in Quezon City on Wednesday evening. Three PDEA agents were also wounded in the confrontation and hospitalized.

Police from the Quezon City Police District special operations unit had been conducting a drug buy-bust operation in a fast-food chain parking lot when they found out they were transacting with PDEA agents. The shootout took place shortly after; the exact circumstances of the shooting are not yet clear.

Authorities have launched parallel investigations through both a joint PNP-PDEA inquiry and a probe by the Philippine National Bureau of Investigation.

"As of now, what is clear ... the PDEA Special Enforcement Services was in the area on a legitimation operation," said PDEA spokesperson Derrick Carreon, PNA reported.

"We will leave it to the Joint Board of Inquiry. We will see the documents tomorrow. For now, our priority is to attend to our wounded personnel," Carreon said.

PNP spokesperson Brig. Gen. Ildebrandi Usana told PNA that the incident, "while serious, will in no way affect the continuing operational relationship and coordination they have long firmed up in the fight against illegal drugs."

"In the interest of determining the truth behind the incident, a joint PNP-PDEA Board of Inquiry will be formed to determine what transpired and who should be held liable," Usana said.

Philippine President Rodrigo Duterte has led a "war on drugs" in the country since coming to power in 2016 by encouraging a severe crackdown on drug dealers and addicts. The often violent campaign has left thousands dead, according to police reports and human rights groups.