Families of British servicemen have been ordered to stop sharing personal details on social media after Islamic extremists threatened to kill a serving solider’s wife in a letter that was shoved through the door of their home, according to the Daily Mirror.

The family is so terrified that they reportedly fled their home.

The letter, entitled “JIHAD – The Holy War For Islam – A warning to the brides of British Soldier Warmongers”, threatens to “destroy the families of unbelievers”.

The full text of the letter reads:

“You have been identified as an unbeliever and a bride of a murderer of the servants of Allah in the Holy Land. Our peoples have suffered at the hands of your husbands who have murdered, killed and raped our women and children. We the servants of Allah intend to avenge our peoples by destroying the families of unbelievers in the land of hate. You along with many others will pay the price for your husband’s destruction in the Holy Land. We now know where you live and will begin to destroy the unbelievers and their families as they have done to us.”

It is signed off “The Circle of Allah – Avengers Serving Allah”.

The threat was made in Lincolnshire, England, which is the county home to nine armed forces bases.

The Ministry of Defence (MOD) is aware of the threat and is working with Lincolnshire Police to investigate.

Chief Inspector Jim Tyner said, “Lincolnshire Police are investigating an allegation of malicious communications where a threatening letter has been sent to the home of a serving member of the armed forces.

“At present we believe this is a one off-incident and would like to hear from any families that had received similar letters. We would like to remind forces families of the need to take particular care. For example, they should review their security settings on social media to ensure they don’t accidentally share personal details,” he added.

The warning also extends to friends who may post on social media platforms and unintentionally give away the location of soldiers.

An MOD spokeswoman said, “Keeping personnel and their families safe is of the utmost importance and all personnel are given clear guidance on appropriate social media use. We do not talk about specific security measures.”