An Isis plan to direct new terror attacks in Europe has been uncovered after the group lost the last sliver of its former “caliphate” in Syria.

Documents on a hard drive, which was dropped by Isis jihadis killed in a desert battle, detail proposals for a “Bureau of Foreign Relations for the Department of Operations in Europe” to organise, arm and fund atrocities.

In a letter passed to The Sunday Times, a senior militant calling himself Abu Taher al-Tajiki told local Isis leaders he was in contact with “individuals who want to work in areas far away from the Islamic State”.

Requesting permission to set up the new “bureau”, he added: “Before they carry out the operations, they will send us the targets if the connection is secure. Otherwise, they do the operation. And by the will of Allah we will meet all of their needs, for those who want it.”

Other letters saw the same writer offer to use sleeper cells across Syria to assassinate targets named by Isis leaders, following a series of murders and bombings in the group’s former territories.

Timeline of the Isis caliphate Show all 19 1 /19 Timeline of the Isis caliphate Timeline of the Isis caliphate ISIS began as a group by the merging of extremist organisations ISI and al-Nusra in 2013. Following clashes, Syrian rebels captured the ISIS headquarters in Aleppo in January 2014 (pictured) AFP/Getty Timeline of the Isis caliphate Abu Bakr Al-Baghdadi declared the creation of a caliphate in Mosul on 27 June 2014 Timeline of the Isis caliphate Isis conquered the Kurdish towns of Sinjar and Zumar in August 2014, forcing thousands of civilians to flee their homes. Pictured are a group of Yazidi Kurds who have fled Rex Timeline of the Isis caliphate On September 2 2014 Isis released a video depicting the beheading of US journalist Steven Sotloff. On September 13 they released another video showing the execution of British aid worker David Haines Timeline of the Isis caliphate The US launched its first airstrikes against Isis in Syria on 23 September 2014. Here Lt Gen William C Mayville Jnr speaks about the bombing campaign in the wake of the first strikes Getty Timeline of the Isis caliphate Isis militants sit atop a hill planted with their flag in the Syrian town of Kobani on 6 October 2014. They had been advancing on Kobani since mid-September and by now was in control of the city’s entrance and exit points AFP/Getty Timeline of the Isis caliphate Residents of the border village of Alizar keep guard day and night as they wait in fear of mortar fire from Isis who have occupied the nearby city of Kobani Getty Timeline of the Isis caliphate Smoke rises following a US airstrike on Kobani, 28 October 2014 AFP/Getty Timeline of the Isis caliphate YPG fighters raise a flag as they reclaim Kobani on 26 January 2015 VOA Timeline of the Isis caliphate Isis seized the ancient Syrian city of Palmyra on 20 May 2015. This image show the city from above days after its capture by Isis Getty Timeline of the Isis caliphate Kurdish forces are stationed on a hill above the town of Sinjar as smoke rises following US airstrikes on 12 November 2015 AFP/Getty Timeline of the Isis caliphate Kurdish forces enter Sinjar after seizing it from Isis control on 13 November 2015 AFP/Getty Timeline of the Isis caliphate Iraqi government forces make the victory sign as they retake the city of Fallujah from ISIS on 26 June 2016 Getty Timeline of the Isis caliphate Iraqi forces battle with Isis for the city of Mosul on 30 June 2017 AFP/Getty Timeline of the Isis caliphate Members of the Iraqi federal police raise flags in Mosul on 8 July 2017. On the following day, Iraqi prime minister Haider Al Abadi declares victory over Isis in Mosul Getty Timeline of the Isis caliphate Members of Syrian Democratic Forces celebrate in Al-Naim square after taking back the city of Raqqa from Isis. US-backed Syrian forces declare victory over Isis in Raqqa on 20 October 2017 after a four-month long campaign Getty Timeline of the Isis caliphate Female fighters of the Syrian Democratic Forces celebrate in Al-Naim Square after taking back the city of Raqqa from Isis. US-backed Syrian forces declare victory over Isis in Raqqa on 20 October 2017 after a four-month long campaign AFP/Getty Timeline of the Isis caliphate Trucks full of women and children arrive from the last Isis-held areas in Deir ez-Zor, Syria in January 2019 They were among the last civilians to be living in the ISIS caliphate, by this time reduced to just two small villages in Syria’s Deir ez-Zor Richard Hall/The Independent Timeline of the Isis caliphate Zikia Ibrahim, 28, with her two-year-old son and 8-month-old daughter, after fleeing the Isis caliphate, on Saturday 26 January 2019 Richard Hall/The Independent

One document detailed the leadership structure of cells hidden in northeastern Syria, including bombmakers and fighters.

The documents said one planned meeting with Isis leader Abu Bakr al-Baghdadi had been delayed and it was unclear whether the proposals were ever presented to leaders, or if other copies existed.

The Syrian Democratic Forces (SDF) have vowed to fight sleeper cells, following several bombings targeting their fighters and international troops from the US-led coalition.

International security services have long predicted that Isis would seek attention and legitimacy through terror attacks after losing its former “caliphate” in Iraq and Syria.

Last week, an audio message from the group’s spokesman was released on propaganda channels urging supporters around the world to launch massacres in revenge for the New Zealand shooting that left 50 Muslims dead.

The foreign secretary warned that people “should not mistake the loss of territory by Isis for final defeat”.

“As they are driven underground, they are adopting insurgency tactics and forming covert networks,” Jeremy Hunt wrote in The Sunday Times.

Baghouz: Syrian Democratic Fighters begin final push to recapture the last sliver of territory controlled by ISIS

“The survival of their murderous ideology does not depend on control of territory. They can still use the internet to raise funds and spread the propaganda that encouraged young people in Britain such as Shamima Begum with such terrible consequences.”

The deadliest Isis massacres seen in Europe, the November 2015 Paris attacks, were directed by the group’s leadership and carried out by a well-trained and armed cell who previously fought in Syria.

Other suspected Isis cells have been arrested in several countries including Germany, where groups of Iraqi and Syrian asylum seekers were found to be planning bombings.

A former Isis militant interviewed by The Independent said that shortly after arriving in Syria in 2015, members of the group’s secret service asked him whether he would be prepared to carry out atrocities in his home country of Germany.

“He was speaking openly about the situation, saying that they have loads of people living in European countries and waiting for commands to attack the European people,” Harry Sarfo said in 2016.

The deadliest Isis terror attack in Europe, the 2015 Paris attacks, was carried out by a cell dispatched from Syria (AP)

But subsequent terror attacks in Europe, including those that struck London and Manchester in 2017, are believed to have been inspired rather than directed by Isis.

Like its predecessor al-Qaeda, the group has reverted to an insurgency in Iraq and Syria, as well as in other nations across the Middle East, Africa and Asia where its fighters are active.

In recent days, updates on Isis’s main propaganda channels have claimed killings in countries including Egypt, Nigeria, Somalia, Iraq and Afghanistan.

Raffaello Pantucci, the director of international security studies at the Royal United Services Institute (RUSI), said terror attacks in Europe are not the group’s biggest priority and it is unlikely to “dedicate massive amount of resources” to plots.

“The idea that Isis may have networks around Europe that might try to do something is possible but my question is why haven’t we seen it yet? What are they waiting for?” he told The Independent.

“Where they carry out their plots is to some degree a reflection of the leadership’s interests, and the core leadership is always going to be more interested in the Levant than they are in Europe.