A woman who said she wanted to marry the militant known as "Jihadi John" has been jailed for four-and-a-half years for spreading Islamic State propaganda.

Zafreen Khadam, 32, was jailed at Sheffield Crown Court after she was found guilty of 10 offences under the Terrorism Act.

The court heard she had suggested in messages to friends that she was going to Syria and would "marry" the infamous ISIS killer.

Detective Chief Superintendent Clive Wain, head of the North East Counter Terrorism Unit said Khadam, from Sheffield, openly supported ISIS, also known as Daesh.

He said his officers reviewed hundreds of hours of video and thousands of social media postings, saying Khadam tweeted up to 20,000 times over one five-week period last year.

He said: "It is clear from the evidence presented that Khadam openly demonstrated support for Daesh and their ideology, using multiple social media accounts to further spread the propaganda of this terrorist organization.

"Khadam has not disputed posting the information, claiming she did so out of curiosity and the belief that she did not consider it to be terrorist material.

"Yet this material glorified terrorism and delivered powerful messages, encouraging terrorist acts and calling upon others to kill."

He added: "Khadam was prolific in her use of social media and showed little regard for the consequences of openly sharing deeply disturbing images and material across a number of digital platforms.

"Much of this material encouraged violent action and was very extreme in the violence it portrayed."

Officers found Khadam had been using 15 social media profiles for posting extreme material.

One of her accounts -- with the Twitter handle Jihadi Princess -- favorited videos, including one that depicted prisoners kneeling in cages in preparation for execution, and which went on to show one person being burnt alive in a cage and another having his throat cut.

Another portrayed the use of children by ISIS, including weapons training and youngsters threatening to kill non-Muslims.

Police said analysis of Khadam's activity on the WhatsApp messaging service showed that she sent a number of ISIS-produced videos and documents to numerous contacts.

Khadam had denied the charges, saying she just wanted to understand ISIS, and did not support it.

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