Literature aimed at children between 11 and 18 on the youth section of the Islamic Society of Britain (ISB) website calls on them to "boycott those who openly wage war against Allah". The article containing that quote, entitled "Imam Hassan al-Banna on jihad", goes on to say: "Jihad is a powerful invigorating yearning for Islam's might and glory ... which makes you cry when looking at the weakness of Muslims today and the humiliating tragedies crushing him to death everywhere.
"Jihad is to be a soldier for Allah. When the bugle calls ... you should be the first to answer the call to join the ranks for jihad."
Other articles on atheism and secularism appear to be against integration. One article is entitled "Zionism, a black historical record", and another, "Israel simply has no right to exist".
The ISB immediately disowned this content after being informed of it by the IoS, and promised to remove it.
In a statement, a spokesman said: "We were not aware of the material being on the website and it is not in agreement and consistency with the ethos and message of the organisation. We will immediately look at this and remove anything that is disagreeable and apologise for any offence that has been caused."
Nadeem Malik, a vice-president of the ISB, added that the literature was the responsibility of the organisation's youth wing, Young Muslims, which has a degree of autonomy.
"Anything that is there is within the remit of the ISB," he said. "I'm not going to justify what is on there. But if it is on there it is a very small part of a much bigger structure that is very much against those views."
He added that the ISB and Young Muslims UK were merged in 1994, and internal debate has created a contradiction of views in the organisation. At the heart of that debate is whether Muslims interpret the Koran literally or within its historical context. This has led to a situation where the mainstream of Muslims in the UK believe in integration, while a small, vocal minority is opposed to Muslims living within a non-Muslim structure of law and education.
Hizb ut-Tahrir, which is non-violent, is one example of the radical groups. It is made up of professionals - managers, academics and doctors - and has a membership of between 2,000 and 3,000. But its strict interpretation of the Koran leads it to instruct its members not to vote in a political system dominated by Kaffirs, or unbelievers.
During this year's election, its members were told that to vote was forbidden by God.Reuse content