A Tower Hamlets-born terrorist “martyr” has been shown inciting Muslims in the borough to “cut the necks of disbelievers” and join a “jihad” (holy war) in Somalia in a video message from beyond the grave.

The man, known only as Talha, appears in a new video released by al-Qaeda linked Somali terror group al–Shabab, which describes him as a “martyr” who died fighting for its cause.

Police have also contacted several well-known British Muslims who are threatened in the video for speaking out against the murder of Drummer Lee Rigby in Woolwich earlier this year.

The British-sounding narrator of the film claims Talha was killed in a raid by British and American forces in November 2012. The government declined to comment on the claim.

In the video, Talha says: “I call upon you today all the Muslim men in Britain, especially the people of Tower Hamlets, in the city I was born in… I call upon you to come to jihad, and raise the banner, humiliate the disbelievers, cut the necks of the disbelievers, and establish the dar-al-Islam (house of Islam).”

One of the people threatened in the video is Ajmal Masroor, a former Lib Dem candidate for Bethnal Green and Bow in 2010.

The release of the video comes after al-Shabab claimed responsibility for the attack on Westgate shopping centre in Kenya last month, which saw 67 people killed, including four Britons.

Dr Usama Hasan, another of the Muslims threatened in the video, said: “Al-Shabab are trying to recruit based on grievances and victimhood, and Muslims in London need to not give in to that.”

Dr Hasan works with the group Quilliam, which recently persuaded the leader of the English Defence League to step down.

He said: “That video uses fascist language to refer to all non-believers and Muslims who disagree with them.

“I refuse to be intimidated by these people. We will continue to engage with their arguments until they are quashed.”