More details have emerged regarding the gunmen who killed 15 people at an Australian beach. New South Wales police commissioner Mal Lanyon revealed that Naveed Akram, 24, and his 50-year-old father Sajid were allegedly motivated by Islamic State (ISIS).

The pair reportedly traveled to the Philippines last month. Authorities found improvised explosive devices and two homemade ISIS flags in a car registered to Naveed at the scene of Sunday’s attack.

Lanyon clarified that Sajid obtained his gun license in 2023, not a decade ago, and had been under surveillance by Australian security intelligence since October 2019. Naveed Akram was arrested at the scene with critical injuries, while his father was shot dead by police.

Australian Prime Minister Anthony Albanese stated that the attack appears to have been inspired by ISIS ideology, which has existed for more than a decade and led to “a preparedness to engage in mass murder.” He described the attack as meticulously planned, noting that the gunmen had carefully positioned themselves on a bridge to maximize their advantage over victims.

As of Tuesday, 25 people remain hospitalized following the attack.