Philippine authorities launched a nationwide manhunt for Senator Ronald dela Rosa, a former national police chief wanted by the International Criminal Court on charges of crimes against humanity, after he slipped out of the Philippine Senate amid a chaotic shooting incident.

According to The New York Times, authorities confirmed they are conducting heightened surveillance at all border crossings and points of departure, and there is no indication dela Rosa has left the country. His location remains unknown.

"Senator Bato is a fugitive from justice, and he should be brought to the I.C.C. to face the charges before him," Justice Secretary Fredderick A. Vida told The Times.

According to the Associated Press, the warrant against dela Rosa — which judges had kept sealed since November before making it public earlier this month — accuses him of the crime against humanity of murder, naming at least 32 victims in killings that prosecutors say took place from July 2016 through late April 2018. In the warrant, ICC judges characterized dela Rosa as an "indirect co-perpetrator" and concluded he "made essential contributions to committing the alleged crime" of murder.

As Duterte's inaugural national police chief, dela Rosa, 64, oversaw the rollout of an anti-narcotics campaign that resulted in the deaths of thousands of people, the majority of them low-level drug suspects. He has denied authorizing extrajudicial killings and has said he is willing to face allegations only before Philippine courts.