Metro Manila (CNN Philippines) — The legal counsel of Albuera, Leyte mayor and a teenage companion were killed in an ambush Tuesday afternoon by still unknown assailants in the city's Barangay Lumbang 2.

Rogelio Bato, lawyer of Mayor Rolando Espinosa who had been named on President Rodrigo Duterte's drug list, died due to multiple gunshot wounds. An 18-year-old girl, who was a student in a city public school, was also killed in the attack.

Police Sr. Supt. Rolando Bade, city police chief, said the two victims where on a black Toyota Hilux owned by Atty. Bato when men on a white van opened at them around 2 p.m.

Bade said witnesses told the police that the assailants' van bore no plate numbers.

The police chief added that investigators were still finding out the motive behind the attack as a manhunt operation had been launched against the gunmen.

Bade said authorities still couldn't say if the assassination was related to the illegal drug trade.

In a previous interview with Chief Supt. Elmer Beltejar, regional director for Eastern Visayas, he said Bato was one of the personalities in the region under investigation in relation to alleged links to the illegal drug trade.

Bato's client, Mayor Espinosa, had previously surrendered at Camp Crame and had called on his son, Kerwin, to do the same to heed the President's call against illegal drugs.

Related: Espinosa to possibly face charges despite surrender

Meanwhile, city mayor Cristina Romualdez, who rushed to the crime scene, condemned the killing and called on authorities to bring the perpetrators to justice.

Tacloban City-based correspondent Wil Mark Amazona contributed to this report.