A teenager ‘jihadi bride’ who fled Britain to join Islamic State terrorists has callously mocked the victims of the Tunisian massacre – as she tried to lure another schoolgirl to join her in Syria.

Amira Abase, 16, wrote that she was laughing out loud – ‘Lol’ in text language – as Britain mourned the 30 citizens murdered on the Sousse beach.

The sickening remark came in an extraordinary series of exchanges with an undercover Mail on Sunday reporter, who Abase believed to be another British teenager planning to run away to join barbaric IS. Abase encouraged her to make the dangerous trip to marry a frontline jihadi fighter.

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Jihadi schoolgirl: Amira Abase, 16, vanished from her East London home to join IS in February of this year

Their online conversation reveals for the first time the full extent of the indoctrination to which Abase has been subjected since she and two school friends vanished from their East London homes to join IS in February.

The messages make clear that she now has an active role as a recruiter and ‘mentor’, planting the seeds of jihad in impressionable teenage minds.

In the exchange she reveals:

Detailed advice and information about how the ‘recruit’ could fool her parents and sneak out of Britain and into Syria via Turkey.

A stark portrayal of the isolated and subservient lifestyle the female recruits face when they arrive in IS-controlled areas.

How she has already lined up a prospective husband for the young girl – but as the jihadi’s SECOND wife.

That she misses her family and life in England but claims ‘Allah replaces all that with something better’.

In the most shocking messages, sent on Friday night, Abase is asked if she had heard about the Tunisian killings. She replies ‘Yhh I have, trusst [me] man’ – but said she hadn’t seen the pictures of the gunman.

Of the 30 British victims, she says, as if in awe, ‘Wow, damn thats a lot.’

Sick reaction: Amira Abase wrote that she was laughing out loud as Britain mourned the 30 citizens murdered on the Sousse beach by Seifeddine Rezgui (pictured)

Schoolgirls: Amira Abase (left), Shamima Begum (right) and Kadiza Sultana (centre) caught on CCTV as they fled the UK for Syria, via Gatwick Airport

Told of the minute’s silence across Britain in memory of the victims, she simply said: ‘Looooool’.

And when the reporter said that some Muslim leaders were condemning the attack, she again replied ‘Looool’.

She appeared sceptical when asked if she agreed the tourists were innocent, replying simply: ‘research’, adding later, ‘like read about it.’

Her comments came hours before IS again revelled in their brutality, releasing a video showing the execution of 25 Syrian soldiers in the historic city of Palmyra by gunmen, some as young as 13.

The footage, released last night, shows the victims lined up in the ancient amphitheatre before being killed in front of a bloodthirsty crowd.

Abase was only 15 when she and fellow GCSE students Shamima Begum, 16, and Kadiza Sultana, 15, ran away from home in February.

All pupils of Bethnal Green Academy, the three girls’ disappearance led to an emotional television appeal by their families, and a desperate operation by British and Turkish police to stop them crossing into Syria to join the estimated 700 British men and women already there.

The Mail on Sunday’s conversation with Abase came as the girls’ parents said they had learned through social media that two of the teenagers had married in the IS terror stronghold of Raqqa, although they declined to say which two. When our reporter asked Abase if she was married, she replied: ‘Can’t tell u.’

Our reporter first contacted Abase after being tipped off that she had opened a new Twitter account, after an earlier one had been closed down.

In April, she created an account with the user name @binttabbas, calling herself Umm Uthman Al-Britaniya. She also referred to herself as Habeshiya, or Ethiopian.

Twitter closed down this account, but a new one appeared under the name Umm Zubayr Britaniya. The followers of Abase’s earlier account announced that she was back online, using this new ID.

Our undercover reporter got in touch, asking to exchange private direct messages. In her first message back, Abase asked: ‘U planning on making hijrah [migration]?’

When the reporter replied yes, she told him to contact her on the encrypted messaging service Kik Messenger. There, when asked how long she had been in Syria, Abase said: ‘Im one of the three girls from Britain so about 4 months. I was only 15 when I made hijrah, so it was the worst.’

Her location could not be verified because, although Twitter and Kik both have functions which reveal a user’s whereabouts, Abase had switched them off.

But last night, Dr Shiraz Maher, an expert on jihadis in Syria and Iraq, said: ‘Having reviewed the dialogues it seems highly credible that this is Amira Abase.’

Dr Maher is a senior fellow at the International Centre for the Study of Radicalisation and Political Violence at King’s College, London.

Our reporter contacted Abase, posing as a 16-year-old girl called Umm Muslimah, who lives in Stratford, East London.

‘Umm’ said she wanted to travel to IS-controlled Syria, but had no ‘tazkyia,’ or introduction from another jihadi.

Abase replied: ‘U don’t need anyone. Just make moves and I can be it [the person who makes the introduction] or find u someone else.’

She told the would-be jihadi bride that she must fly to Istanbul first, and tell her parents that day that she is going to ‘revision classes’.

Abase also advised against booking a plane ticket online, as that would require handing over credit card details and passport numbers.

She told ‘Umm’ that she lives in the IS stronghold of Raqqa, where all would-be jihadi brides are eventually brought and kept imprisoned in all-women’s safe-houses called maqqars, without access to mobile phones or internet.

Abase told our reporter: ‘when u first come in to dawla [IS territory] ur put in to a sisters house but u cant go out, no net and no phone allowed. If you wana get married its better u know his name before hand so wen u get in to the sisters house u can ask for him.’

Asked if she thought 16 was too young to be married, she said: ‘loool no. aisha [the Prophet Mohammed’s favourite wife] got married when she was 9.’

Abase advised ‘Umm’ to go to an Asian travel agent in Brick Lane, in the East End, where they take cash and do not ask questions.

When the reporter sounded wary about travelling alone, Abase said: ‘So many sisters do it... I will give you contacts that will come and help you. I’ll get them ready for when u reach Istanbul. … just make a story and make moves.’

Abase then advised the reporter on what to bring with her into Syria. She said: ‘They have the worst bras here, so get lots of bras. Get black khimars [female long Islamic dress] and jilbabs [head-to-foot female gown] and niqabs [face veils] only black. Get underwear, get tops and skirts and stuff.’

Abase added: ‘Bring as much money as u can.’

Throughout Abase’s exchanges with the reporter, which lasted two weeks, one theme was ever-present: a constant pressure on the would-be traveller to marry a jihadi as soon as possible after entering IS territory. Abase said: ‘when r u planning on coming and do u wana get married?’

Abase then revealed that she had already found a prospective groom a Lebanese-Australian frontline fighter, but he was already married, despite being only 18. Abase added: ‘Do u mind being a second wife or na [not]?’

She also explained that she would have to get her new husband’s agreement if she wanted to attend Arabic or religious classes.

Joining jihad: Amira Abase pictured last year before fleeing Britain to Syria in February to join Islamic State

In April, Abase’s father admitted taking his daughter to an extremist rally when she was 13. Abase Hussen, 47 was also part of a flag-burning mob, screaming in rage at a protest outside the US Embassy in London, in 2012

Despite her fanaticism, Abase also revealed how she missed aspects of her life in East London, and how she coped living away from her family.

She said: ‘U miss it but u get over it because u leave everything for the sake of Allah and Allah replaces all that with something better.’

Asked if she missed her family, she replied: ‘Loool of course. How can u not miss ur family.’

When the reporter asked how she coped, Abase said: ‘I dunno really u just do tbh [to be honest].’

In April, Abase’s father admitted taking his daughter to an extremist rally when she was 13.

Abase Hussen, 47 – who blamed police for failing to stop his daughter fleeing to join IS – conceded the teenager was ‘maybe’ influenced by the rally organised by banned terror group Al-Muhajiroun.

He was also part of a flag-burning mob, screaming in rage at a protest outside the US Embassy in London, in 2012

His daughter’s first Twitter account was closed down soon after she posted a quote about Muslims and their ‘enemies’ by Sheikh Abdullah Azzam, the spiritual mentor of Osama bin Laden.