A teenager has pleaded guilty at the Old Bailey to inciting terrorism by encouraging the murder of police officers in Australia.

The 15-year-old, who cannot be named for legal reasons, made the plea via video link from Manchester Crown Court.

Although he is from Blackburn, Lancashire, the charge states he incited a person to commit an act of terrorism wholly or partly outside the UK - at a parade to commemorate ANZAC Day.

The court heard how he had exchanged thousands of instant messages with Sevdet Besim, an 18-year-old from Australia, in March 2014.

In one message, the teenager told Besim: "Suggest you break into someone's house and get your first taste of beheading."

The Australian replied that it "seemed a little risky", according to the prosecution.

Mr Justice Saunders has requested pre-sentence reports to determine whether "indoctrination" played any part in the boy's case.

"I want some assessment of how and why it occurred and what measures could be taken in order to reverse that process," he said.

"Dealing with someone of this age is an extremely difficult sentencing process and I will need all the help I can get."

A second charge - of inciting terrorism overseas in relation to beheading a person in Australia - was dropped by the prosecution.

Police in the UK found messages the teen had been sending and alerted police in Melbourne, who then arrested five teenagers who they alleged had been plotting an Islamic State inspired attack.

The teenager is currently being held at a youth detention centre, and sentencing has been adjourned until 3 September.

Every year on 25 April, ANZAC Day ceremonies commemorate the Australian and New Zealand Army Corps' First World War battle in Gallipoli.

The parades were particularly significant this year - marking a century since the battle took place - but security had to be stepped up across the country.

In a separate case, two Melbourne teenagers were charged with planning an "Islamic State-inspired attack".