Multiple gunshots were heard inside the Senate of the Philippines on Wednesday as security tensions escalated around Senator Ronald dela Rosa, who is wanted by the International Criminal Court over allegations linked to the country’s deadly anti-drug campaign.

According to journalists inside the Senate building, at least five shots were heard shortly after armed soldiers wearing protective gear entered the area, prompting reporters to flee for safety.

Dela Rosa, a close ally of former Philippine president Rodrigo Duterte, has reportedly been staying inside the Senate since Monday to avoid arrest and possible transfer to the Netherlands, where the ICC is pursuing crimes against humanity charges connected to the controversial anti-drug crackdown.

Senate President Alan Peter Cayetano later claimed during a livestream that the Senate was “under attack,” though no further details were immediately provided.

Another Duterte ally, Senator Robin Padilla, was seen urging journalists to leave the area as tensions grew inside the building.

Earlier in the day, Dela Rosa appealed to members of the military and his former classmates from the Philippine Military Academy to oppose any attempt by the government of President Ferdinand Marcos Jr. to hand him over to international authorities.

Dela Rosa served as police chief between 2016 and 2018 during the early years of Duterte’s administration, when thousands of people were killed in anti-drug operations, according to human rights groups.

Duterte himself was arrested last year and transferred to The Hague, where he remains in detention awaiting trial before the International Criminal Court.

Dela Rosa had largely stayed out of public view since November before reappearing earlier this week during a Senate vote that strengthened the position of Duterte allies in the chamber.