Authorities say the shooting was not an ‘attack on the Senate’ and identified the person who fired the first shot.

Philippine authorities are investigating Senate security officers who discharged their weapons without provocation while a senator facing an International Criminal Court (ICC) arrest warrant took shelter inside the legislative building and later escaped.

Juanito Victor Remulla, secretary of the interior and local government, on Tuesday said the May 13 shooting was not an “attack on the Senate”, adding that there was no one in the area when the gun was fired.

Remulla identified Senate Sergeant-at-Arms Mao Aplasca as the person who fired the first shot.

National Police chief Jose Melencio Nartatez, who said investigators recovered 44 fired cartridges traced to four firearms, stated that Aplasca had been called to a police inquiry to have his gun tested, but he had not yet complied.

CCTV footage subpoenaed by investigators from the Senate appeared to show him firing a rifle.

Remulla said the president has been informed of the findings, but he has not “given instructions yet”. The case is being handed over to the Department of Justice for further investigation.

Nartatez said dela Rosa left the legislative building and got into a car registered to his ally, Senator Robin Padilla, which left for an unknown destination.

“All evidence points that there was no attack on the Senate,” Remulla said, adding that government agents “never set foot” inside the Senate building.

The shooting happened last week, when Senator Ronald Dela Rosa, a 64-year-old former police chief and key figure in ex-President Rodrigo Duterte’s war on drugs, took refuge in the Senate on May 11 after the ICC confirmed having unsealed his arrest warrant on suspicion of crimes against humanity.

The Senate was rocked by the sounds of dozens of gunshots and armed soldiers who stormed the building to arrest him later that day.

Dela Rosa was Duterte’s top lieutenant and oversaw a fierce crackdown on drug dealers, which saw thousands shot dead in extrajudicial killings.

Duterte was arrested last year and is awaiting trial before the ICC in The Hague.