Senator Ronald "Bato" dela Rosa on Monday admitted that failure of intelligence may have played a part in the deadly bombing at the Mindanao State University in Marawi City on Sunday which killed at least four people and injured 50 others.

"The failure of intelligence is possible because they failed to monitor it. If they were able to monitor it, it could be a failure to act on intelligence," said Dela Rosa, a former Philippine National Police chief.

He, however, stressed that it would be "very unfair" for government security forces if he would conduct an investigation against them on the supposed lapses.

"It would be very unfair for our security forces if we made them accountable due to the supposed failure of intelligence," he said. "If they did not monitor anything, it means it was below their radar."

When asked about potential backlash from the public due to the security forces' failure to gather intelligence about the attack despite having confidential and intelligence funds, Dela Rosa answered: "People will be asking for accountability. I have been with security forces; I know their situation. If it will happen, it will happen."

Under the 2023 General Appropriations Act, the National Intelligence Coordinating Agency was given P1.385 billion, while the National Security Council received a total of P418.8 million.

Islamic State militants earlier claimed responsibility for the deadly attack in Marawi, which was once overran by Islamist militants for several months in 2017.

In the message application Telegram, the group admitted the attack, claiming its members had detonated an improvised explosive device.