BRITAIN AT ALERT AS MRS. TERROR MAY HAVE RETURNED TO UK.

A British woman who ran off to join ISIS in Syria is feared to have returned to the UK with two jihadis in tow.

Sally Jones signed up for the extremist group in 2013 with her husband Junaid Hussain, who together have been dubbed 'Mr and Mrs Terror'.

But reports suggest she may have been seen in Birmingham this week with two other people, both said to be aged around 20.

HUSSAIN

Former rock musician Jones, 45, and Hussain, 21, were this week named as two ISIS recruiters seen boasting online about a planned terror attack in the UK.

They told undercover reporters posing as wannabe jihadis to carry out so-called 'Lone Wolf' attacks, and even sent them bomb-making guidebooks.

The militants also revealed that the Queen and the Royal Family would be targeted with pressure cooker bombs at tomorrow's VJ commemorations.

Police are believed to be investigating the reports Jones has returned to the UK and airports are being watched.

A source told the Daily Mirror: 'This is worrying but Special Branch officers are working on this to track her down.'

The current terror threat level for international terrorism is 'severe', meaning an attack is 'highly likely'.

The Metropolitan Police are yet to comment on the reports but Police Scotland said this week that it is working with the London force to deal with the threat.

Counter Terrorism officer ACC Ruaraidh Nicolson said: 'We remain alert to all terrorist threats that may manifest here or where individuals overseas may seek to direct or inspire others to commit attacks in and against the UK.'

Earlier this week it emerged that Sky News reporters posing as male and female jihadis on Twitter and in chatrooms had communicated with Hussain, a 21-year-old from Birmingham, and Jones, a former punk from Chatham in Kent.

Hussain runs the ISIS recruitment arm in the terror group's de facto capital of Raqqa in Syria and is a top-five target for the U.S. Secret Service. Jones is working alongside her husband in Raqqa recruiting female militants.

In a series of conversations on encrypted messaging sites over a four months, the reporters convinced Jones that they wanted to make a bomb. 

Jones then gave detailed instructions on how to construct a pressure cooker explosive and insisted on seeing receipts to prove they had bought the materials. 

She revealed she had another potential bomber in Scotland and two others who had so far failed to carry out attacks and urged the undercover reporters to start a gang themselves.

She later sent details of the plot to attack the Royal family at the VJ commemorations on Saturday, which were passed on to the Metropolitan Police's anti-terror branch.

One reporter later travelled to the Turkish city of Urfa near the Syrian border to meet an ISIS security chief tasked with looking after foreign jihadists while they underwent terror training.

He claimed four or five recruits were British who had returned to Britain to carry out an attack.