The Philippines Bureau of Immigration said on Tuesday that the two alleged gunmen behind the mass shooting at Sydney's Bondi Beach travelled to the Philippines on November 1 aboard Philippine Airlines Flight PR212 from Sydney to Manila and onward to Davao.

A spokesperson for the bureau said that Sajid Akram, 50, an Indian national and Australian resident, travelled on an Indian passport, while his son Naveed Akram, 24, an Australian national, used an Australian passport. Both arrived together on that flight.

They departed on November 28 on the same flight number, PR212, from Davao via Manila back to Sydney, weeks before the assault that killed 15 people.

The attack on Sunday was Australia's worst mass shooting in nearly 30 years, and is being investigated as an act of terrorism targeting the Jewish community.

Also Read: Sydney gunmen travelled to Philippines on Indian passport

It was not immediately clear what activities they undertook in the Philippines or whether they travelled elsewhere after landing in Davao, a city in Mindanao, a region where terrorist groups, including ISIS-linked factions, have operated.

In 2017, Islamic State-inspired militants seized parts of the southern city of Marawi and held it through five months of ground offensives and air strikes by the military.

The siege of Marawi, the country's biggest battle since World War Two, displaced some 350,000 residents and more than 1,100 people were killed, mostly militants.

While the Armed Forces of the Philippines is validating the reports, its spokesperson said in a statement the military is closely coordinating with relevant agencies on matters involving the movements of foreign nationals and potential terrorist ties.