Piccadilly Circus in London, England (file)
Piccadilly Circus in London, England (file)Flash 90

New details in connection to the arrest of four Islamic terrorists on Tuesday reveal that the cell was affiliated with the Islamic State (ISIS), and planned a brutal beheading - or beheadings - on the streets of London.

MI5 (British intelligence) and police monitored the four, arresting them while they were in the "early stages" of planning a "significant" attack. Scotland Yard indicated the four intended to import ISIS's beheadings of westerners in Syria that have shocked the world, reports the UK's The Telegraph.

Con Coughlin, defense editor of the British paper, confirmed to Fox News on Tuesday that the plan was to behead civilians in public citing intelligence officials.

"The material that we have from Scotland Yard and the intelligence services is they have uncovered the first ISIS plot here in the UK," Coughlin said. "Basically, (they were) British jihadists coming back to London and wanting to carry out a plot, and I’m told the plot was to behead people on the streets of London."

Coughlin continued "what I’m told about this plot is this group did recently come back from Syria, was planning to carry out beheadings - I say plural - on the streets of London in the next few days or so."

Scotland Yard released a statement after the arrest saying "these arrests and searches are part of an ongoing investigation into Islamist-related terrorism."

The plan mirrors plots by a large Australian ISIS cell that was busted in mid-September, which had planned to behead a random member of the public.

Just days later in Norway, another ISIS cell was foiled ahead of executing its plans to behead an entire family and film it as a "warning" to Western states intervening against ISIS in Iraq and Syria.

In the UK, roughly 500 Britons are thought to have joined ISIS in Syria, and about half of that number is feared to have returned home, potentially to carry out domestic terror attacks.

Islamist terrorists have already committed a brutal beheading in London in the ghastly murder of British soldier Lee Rigby on the city's streets in broad daylight last May. Apparently the current ISIS cell and those like it hope to repeat the act.