Muslim community workers have accused MI5 of blackmailing and harassing them to work for the security service or face detention in the UK and overseas.

MI5 (Military Intelligence, Section 5), is UK's counter-intelligence and security agency and is part of the intelligence machinery alongside the Secret Intelligence Service (SIS or MI6), Government Communications Headquarters (GCHQ) and the Defence Intelligence Staff (DIS).

Now five Muslim workers have made official complaints to the police, to the body which supervises the work of the security service and to their local Member of Parliament Frank Dobson, The Independent said on Thursday.

The allegation raises concern about the coercion of young Muslim men by the security service and smack of racism, Islamophobia.

"The only thing these young people have in common is that they studied Arabic abroad and are of Somali origin. They are not involved in any terrorist activity whatsoever, nor have they ever been, and the security services are well aware of this," said Sharhabeel Lone, the chairman of Kentish Town Community Organisation (KTCO).

He said "these incidents smack of racism, Islamophobia and all that undermines social cohesion".

The harassed Muslim workers have decided to go public with their complaints in a bid to stall similar tactics being used against the community in the future.

"Threatening British citizens, harassing them in their own country, alienating young people who have committed no crime other than practising a particular faith and being a different colour is a recipe for disaster," Sharhabeel stressed in a letter to Lord Justice Mummery, who heads the Investigatory Powers Tribunal that oversees the work of the security services.

He said when people are terrorised by the very same body that is meant to protect them, sowing fear, suspicion and division, "we are on a slippery slope to an Orwellian society".

Three of the men said they were detained at airports outside the UK on the orders of MI5 after leaving the country on family holidays last year.

They were interrogated by MI5 officers, who accused them of links to Islamic extremism. According to the British daily, the agents said they would end travel restrictions and threat of detention in return for their co-operation. When they refused, some of them received "intimidating phone calls and threats".