Malacañang on Thursday said that Senate Sergeant-at-Arms and retired Police Major General Mao Aplasca fired the first “warning shot” during a shooting incident at the Senate on Wednesday night, May 13, 2026, prompting a National Bureau of Investigation (NBI) agent to fire back.

In a press briefing, Palace Press Officer Undersecretary Claire Castro said the Office of the Senate Sergeant-at-Arms (OSAA) initiated the gunfire after personnel encountered NBI agents in the Government Service Insurance System (GSIS) side of the Senate premises.

According to Castro, OSAA personnel were alerted after learning that NBI agents were present at the GSIS area, prompting them to gear up and prepare for an operation.

“Noong nakita ng [Office of the Sergeant-at-Arms] na mayroong NBI agent sa GSIS, katabi ng Blue Guard, nakita na agad na naka-gear up ang OSAA, nag-vest at naghanda sa isang operation. Pagdating sa bridge sa GSIS premises, tinanong ng OSAA ang isang NBI agent na nakaupo lamang kasama nga ang isang Blue Guard ng GSIS,” Castro said in a press briefing Thursday, May 14.

“Nagpakilala na [ang] NBI agents at no'ng nagsabi sila ng pagkakakilanlan, agad nagpaputok ng warning shot si Sergeant-at-Arms Mao Aplasca at dahil do'n napilitan ding magpaputok ng warning shot ang NBI agent,” she said.

Meanwhile, NBI Director Melvin Matibag said that a total of around six warning shots were fired by the NBI as a response after an OSAA official allegedly fired first.

During the same briefing, Philippine National Police (PNP) Chief Police General Jose Melencio Nartatez Jr. said that they estimate “not less than 30” shots were fired during the shooting, and said that bullets came from inside the Senate.

Authorities are continuing to verify the details of the incident, including the number of shots fired and the circumstances that led to the exchange.

Castro also clarified that there was ”no assault” committed by NBI personnel inside the Senate and denied that any arrest operation targeting Senator Ronald “Bato” dela Rosa was underway at the time.

“Walang assault na ginawa ang [National Bureau of Investigation] agents sa Senado at pangalawa, walang operasyon ang NBI o [Philippine National Police] na arestuhin si Senator Bato,” Castro said.

The NBI has not yet confirmed reports on whether dela Rosa, who has been under protective custody since May 11, has already left the Senate.