Updated

A teenage suspect discussed with a British accomplice packing a kangaroo with explosives before setting it loose on Australian police officers, prosecutors alleged on Thursday.

Sevdet Ramadan Besim was ordered in the Melbourne Magistrates Court on Thursday to stand trial in the Victoria state Supreme Court on charges that he planned an Islamic State group-inspired terrorist attack at a Veterans' Day ceremony that included targeting police officers in April last year.

Besim, 19, pleaded not guilty to four charges relating to a plot to attack commemorative services in Melbourne or the neighboring city of Dandenong to mark ANZAC Day, the annual April 25 commemoration of the 1915 Gallipoli landings in Turkey. The campaign was the first major military action fought by the Australian and New Zealand Army Corps during World War I and hundreds of thousands attend commemoration services around Australia. Besim faces a potential life sentence in prison if convicted.

Besim and four alleged conspirators were arrested in Melbourne a week before ANZAC Day. He has been in custody since.

Prosecutors alleged in court documents that Besim discussed with a British-based accomplice in online conversations that a kangaroo could be packed with explosives, painted with "the IS symbol" and set loose on police.

Besim was also accused of planning to use a car to run over, then behead, a police officer.

Besim allegedly said in online communications he was "ready to fight these dogs on there (sic) doorstep."

"I'd love to take out some cops," Besim is alleged to have written. "I was gonna meet with them then take some heads."

Police allege Besim was motivated by an extremist ideology and had expressed support for terrorist organizations, particularly the Islamic State movement.

A British court in October sentenced a 15-year-old boy from Blackburn, northwestern England, for his part in the ANZAC Day plot.

In passing sentence in the Manchester Crown Court, Judge John Saunders said the teenager, who can't be named because of his age, would only be released when he was no longer a danger to the public. Saunders handed down a life sentence with no chance of parole for five years.