An Isis supporter planned to launch simultaneous terror attacks at Big Ben, Westfield shopping centre, Heathrow Airport, on public transport and numerous others targets, a court has heard.

While allegedly plotting how to mount bomb and car attacks, Umar Haque is accused of brainwashing children he taught at an Islamic school and mosque and making them act out atrocities.

The 25-year-old and three co-defendants denied terror offences at the opening of their trial at the Old Bailey.

The court heard Mr Haque became “fascinated” by the Westminster attack in March and discussed bringing his own “death squad” to the capital.

In a bugged conversation four days after the first Isis-claimed attack in London, he allegedly told a friend: “So what I want to personally is launch different attacks in all the different areas, one in Westminster, one in Stratford, one in Forest Gate, one...in so many different areas, yeah.

"Immediately there's one focus to all the police. Get off the streets. Civilians get off the streets. London will be, not just Westminster attack, entire London...we're here to cause terror, my brother.

Umar Haque allegedly showed extremist propaganda to children he taught at the Lantern of Knowledge Islamic school (Google Streetview)

“We are a death squad sent by Allah and his messengers to avenge my Arab brothers' blood.“

Mark Heywood QC, prosecuting, told jurors Mr Haque and his fellow conspirators were set on carrying out violent attacks with others on civilian and police targets in 2016 and early 2017.

"Umar Haque was fascinated by the warped and extreme ideology of Islamic State [Isis],” he added.

"He had identified methods and targets. Those targets were numerous but included for example, the Queen's Guard, the courts, Transport for London, Shia Muslims, Westfield, banks in the City of London, Heathrow, west London, Parliament, Big Ben, the English Defence League or Britain First, embassies, media stations.”

Abuthaher Mamun, 19, Muhammad Abid, 27, and Nadeem Patel, 26, who knew Haque through his local mosque in Barking, east London, are accused of aiding his plot.

Mr Mamun assisted attack planning and raised money through trading in options, Mr Abid was involved in “discussion and lower level of support” while Mr Patel agreed to provide a gun, jurors were told.

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While they continued to plot, Mr Haque allegedly showed children videos of beheading in a bid to foster extremist ideology at an Islamic school where he worked.

He taught pupils aged between 11 and 16 at the Lantern of Knowledge Islamic school in Leyton, east London, between September 2015 and September 2016.

Mr Heywood said told the court Mr Haque showed his pupils images of guns, burning of passports and beheadings with a knife or sword to “encourage them into his mindset”.

He had also assumed the role of a teacher at the Ripple Road Mosque in Barking, jurors were told, which Mr Mamun was involved in running.

In the months before his arrest early last year, Mr Haque allegedly “manipulated” children, telling them he intended to die a martyr and Isis was “good”.

The court heard he showed them “horrifying” images, including one of a dead boy, saying they would meet the same fate if they did not “join” and promise to become a martyr.

Mr Haque allegedly made the children do “push-ups, races and grappling” and act out the roles of police and attackers in scenarios involving weapons and a car bomb, while he shouted “Allahu Akbar”.

Mr Heywood told jurors the defendant swore the children to secrecy, adding: “He said whatever they spoke about in the mosque must stay in the mosque.”

In pictures: Westminster attack Show all 9 1 /9 In pictures: Westminster attack In pictures: Westminster attack An air ambulance lands after gunfire sounds were heard close to the Palace of Westminster in London PA wire In pictures: Westminster attack MPs wait until the situation is under control in Westminster. 'The alleged assailant was shot by armed police,' David Lidington, leader of the House of Commons, told the house. BBC News In pictures: Westminster attack Crowds gather in Westminster after shooting incident, which police are treating as terror attack BBC News In pictures: Westminster attack Police were also called to an incident on Westminster Bridge nearby AP In pictures: Westminster attack Early reports indicate the car, which mounted the pavement on Westminster Bridge and mowed into around a dozen people, was the same vehicle which then rammed into the railings of the Palace of Westminster, just around the corner Reuters In pictures: Westminster attack Security sources described the suspected assailant as a middle-aged Asian man, who is understood to have left the car before attacking a police officer with a seven-to-eight inch knife PA wire In pictures: Westminster attack Police have asked people to avoid the immediate area to allow emergency services to deal with the ongoing incident AP In pictures: Westminster attack One woman has died and a number of others, including the police officer, have been hurt, according to a junior doctor at St Thomas' Hospital Reuters In pictures: Westminster attack At least three gun shots were heard by those inside Westminster, and proceedings in the House of Commons have been suspended AP

Mr Haque came to the attention of authorities when he tried to travel to Turkey from Heathrow in April 2016, with the route closely watched after being used by hundreds of British jihadis who joined Isis in Syria.

An intelligence operation saw conversations in Mr Abid’s home and car, and Mr Haque’s vehicle covertly recorded, the court heard, showing the pair discuss fears of a “snitch” and justification for killing civilians during one five-hour conversation.

Mr Haque allegedly discussed using a car, leaving bombs in a lift, and going for “a quick spin” around Westminster, and separately compared Isis gaining more territory to “us winning the world cup”.

He and Mr Mamun are charged with preparing acts of terrorism between March and May 2017.

Mr Haque is further charged with preparing terrorist acts by leading exercises with children at the mosque and dissemination of terrorist publications at the Lantern of Knowledge school.

Mr Abid is accused of having information about Haque's plans and Patel is charged with plotting with Haque to possess a firearm or imitation firearm.

The defendants, who are from east London, have denied those charges.

But Mr Haque has admitted separate charges over the collection of terrorist information and dissemination of terrorist publications at the mosque, while Mr Patel has admitted possessing a prohibited weapon.

The trial continues.