Curtis Cheng

Two people, including a 15-year-old boy, were arrested on Thursday in Sydney over a terror plot targeting a government building, with authorities expressing alarm at the age of those being radicalised.

Four people were arrested in Australia today over the terror-linked murder of a police employee after coordinated raids by more than 200 officers on properties across Sydney.

An Australian mosque reportedly visited by a 15-year-old boy before he shot dead a civilian police employee in an "act of terrorism" has been raided, police said today, as authorities boosted efforts to tackle youth radicalisation.

Two people, including a 15-year-old boy, were arrested on Thursday in Sydney over a terror plot targeting a government building, with authorities expressing alarm at the age of those being radicalised.

Four people were arrested in Australia today over the terror-linked murder of a police employee after coordinated raids by more than 200 officers on properties across Sydney.

An Australian mosque reportedly visited by a 15-year-old boy before he shot dead a civilian police employee in an "act of terrorism" has been raided, police said today, as authorities boosted efforts to tackle youth radicalisation.