The father and son duo suspected of carrying out a massacre at Sydney’s famed Bondi Beach on Sunday were “driven by Islamic state ideology,” police say, and they recently traveled to a part of the Philippines – which has previously been a hotbed of Islamic extremism.

The Hyderabad residence of Sajid Akram, one of the two men identified as attackers in the Sydney shooting, was found locked and vacant when reporters visited the premises this week, even as police indicated that his brother is believed to be staying there.

Sajid Akram, a 50-year-old man behind Australia’s worst mass shooting in nearly 30 years, is of Indian-origin, say authorities. After earning a college degree in Hyderabad, he migrated to Australia in November 1998 in search of employment.

Sajid Akram, originally from Hyderabad, India, was a suspect in a mass shooting at Bondi Beach, Australia. He migrated to Australia in 1998 and was radicalized with his son, Naveed. The investigation examines their ties to jihadist networks and their travel to the Philippines for military training.

Sajid Akram was shot dead at the scene, while Naveed was arrested and remains under police guard in hospital with serious injuries.