National Bureau of Investigation (NBI) Director Melvin Matibag on Friday warned that the growing number of death threats posted on social media is becoming a dangerous "norm" that threatens public safety and national security.

Matibag said the normalization of online death threats has become a serious concern for law enforcement authorities.

"It seems like they're normalizing the death threats. As law enforcement, this is very alarming. That's why I'm saying that it's becoming a norm. We need to stop this," he said.

He noted that even high-ranking government officials have become targets of threats openly posted on social media.

"It's very alarming because even if our government officials are high-ranking, there are ordinary people who will give threats. That's why I'm saying that our national security will be under attack right now," Matibag added.

The NBI chief issued the warning as the bureau conducts a case build-up into hundreds of social media posts allegedly threatening Sen. Risa Hontiveros.

The investigation was launched after Hontiveros' office sought the bureau's assistance following a wave of online posts calling for or threatening her death after the killing of pro-administration vlogger Alicia Lipata, popularly known as Mima Alicia.

Matibag said the NBI will subject the reported social media accounts to forensic and cybercrime analysis to determine whether criminal charges should be filed.

He emphasized that the bureau's investigation will be based on evidence, due process, and the rule of law, stressing that the probe is neither politically nor personally motivated.