But what if an Iranian group dedicated to suicide bombings says it?
...A Tehran-based group claimed yesterday it was trying to recruit Iranians and other Muslims in Britain to carry out suicide bombings against Israel.
The Committee for the Commemoration of Martyrs of the Global Islamic Campaign, which claims to be independent but has the backing of the regime, said it is targeting potential recruits in Britain because of the relative ease with which UK passport-holders can enter Israel.
Mohammad Samadi, a spokesman for the group, told the Guardian that striking at Israel was the priority of his recruitment drive. "The first target is Israel. For us, that is the battlefield," he said. "All the Jews are targets, whether military or civilian. It's our land and they are in the wrong place. It's their duty to pay attention to safety of their own families and move them away from the battlefield," he said.
Mr Samadi's group was participating in a recruitment fair for "martyrdom seekers" being held in the grounds of the former US embassy in Tehran. Several hundred volunteers have signed up for missions in the past few days.
Volunteers attracted to his group were asked to complete forms specifying whether they prefer to carry out operations against "the Quds occupiers" [Israel], the British author Salman Rushdie - subject of a death sentence passed by Iran's late spiritual leader, Ayatollah Ruhollah Khomeini, over The Satanic Verses - or "the occupiers of Islamic lands", the US and Britain.
...Western diplomats played down the significance of the group's threat, saying it was primarily a campaign to gather signatures of protest against Israel rather than recruiting bombers.
While the committee claims to be independent it has previously been linked with the Revolutionary Guards. It claims it has gathered 52,000 recruits - of whom 30% are women - since forming two years ago. According to the group, recruits are instructed in target planning and military discipline before progressing to intensive urban guerrilla warfare training, involving the use of bomb belts.
When asked how Iranian volunteers would get into Israel, Mr Samadi cited the precedent of Asif Mohammed Hanif and Omar Sharif, two British Muslims who attacked a bar in Tel Aviv, killing three Israelis, in 2003 after entering Israel as tourists and then posing as peace activists. Hanif blew himself up at the scene while Sharif fled, but was found drowned in the Mediterranean.
"That shows that it has not been difficult getting into Israel," he said. "Do you think getting hold of a British passport for an Iranian citizen is hard? Tens of passports are issued for Iranian asylum seekers in Britain every day. There are hundreds of other ways available to us, such as illegal entry [into Britain], fake passports, etc.
"Britain and other European countries have a lot of disaffected Muslims who are ready. We understand the suspicion with which Britain, America and other western countries regard their Muslim populations. We don't condemn them for this because we believe every Muslim has the potential to turn into a bomb against the west."