LONDON (AFP) - A British court on Thursday (Oct 15) sentenced a 16-year-old girl to a 12-month rehabilitation programme after she was arrested by police investigating an Islamic State in Iraq and Syria (ISIS)-inspired "massacre" plot on an Anzac Day parade in Australia.

The Manchester teenager, who cannot be named, had earlier pleaded guilty to two offences of downloading terrorist information as Manchester Youth Court heard how she had become radicalised online and intended to hack into the White House.

She was first detained in April along with Britain's youngest convicted Islamic terrorist.

He was sentenced to a minimum of five years in jail earlier this month for masterminding the plot to behead police officers at a memorial event in Melbourne from his bedroom in Lancashire, northern England, when aged just 14.

Police found that the pair had exchanged more than 2,000 WhatsApp messages and that she had downloaded instructions on how to make a bomb.

However, there was no evidence that she was aware of or involved in the Anzac Day plot, the court heard.

The girl, flanked in court by her mother and an aunt, told judge Khalid Qureshi on Thursday (Oct 15): "I deeply regret what I have done. I wish to make changes if I get the chance to prove I am not a terrorist."

On handing down the 12-month intensive referral order, judge Qureshi said: "It must be every parent's worst nightmare to discover their child has been accessing material they should not, of whatever type."

Her lawyer Nasir Hafezi told the court she had been lured into an online "fantasy world".

"She became obsessed with the concept of suicide bombing and martyrdom, which she saw as a way out," he said.

The teenager used her school's IT system to search for information on militant group ISIS and its executioner "Jihadi John", later telling police: "I thought I would one day hack into the White House."

A referral order is a community sentence often imposed on youths that requires them to carry out rehabilitative and restorative programmes.