John Emott

So there's a lot of interest on the part of authorities to understand what exactly happened on this trip and why they ended up going to the Philippines.

The Australians haven't said very much, but Filipino authorities have confirmed that they did list Davao, which is a major city in the southern Philippines, as a destination.

Davao is on the island of Mindanao, which has...

hosted Islamic insurgencies in recent decades, some of which have been very violent and have interacted with regional terror cells and even global groups like the Islamic State.

So there are a lot of questions about what exactly the two men would have been doing in the southern Philippines if they received training.

That's something that authorities are actively looking into.