A man holds a photograph and wears the medals of a relation who was a war veteran during the ANZAC (Australian and New Zealand Army Corp) Day march through central Sydney, Australia, April 25, 2016. [Photo/Agencies]

The arrest of a 16-year-old boy in Sydney hours before the Dawn service of Anzac Day started reminded the country that a new war on terrorism could not be ignored.

Australian counter-terrorism authorities arrested a 16-year-old teenager at his western Sydney home late Sunday.

Australian Broadcasting Company (ABC) reported that the matter was heard in the Children's Court on Monday morning, and the boy did not apply for bail. Papers tendered to the court showed the teenager was allegedly trying to obtain a gun to carry out an Anzac Day terror plot -- an offence that carries a maximum penalty of life imprisonment.

This is the second year in a row when authorities say they thwarted an alleged terror plot targeting Anzac Day commemorations.

Security was beefed up at the Anzac commemoration ceremony held at Sydney's Hyde Park.

However, the news failed to deter Sydneysiders and visitors from flocking to get a glimpse of the military bands and veterans marching along Elizabeth Street in the CBD.

In South Australia, about 6,000 military veterans and current servicemen and women took part in this year's Anzac Day parade in Adelaide, with some 8,000 crowd watching.

In Western Australia, heavy rain failed to dampen the enthusiasm of the estimated crowd of 30,000 or about 6,500 people who participated in the Anzac Day parade.

The Australian Associated Press reported that hundreds of Australians and New Zealanders slept out to be at the dawn service at Gallipoli, Turkey where the Anzac story began.

Dawn services were also held in Kabul by Australian Defence Force personnel on deployment in Afghanistan.