Prayers began with the arrival of a detachment of heavy-set men, hard eyes staring through small slits in their headscarves.
Watched by a posse of police, they spread a tarpaulin on the road in front of the boarded-up gates of Finsbury Park mosque in north London, demanding repeatedly that people should keep their distance.
Proceedings got under way with a vituperative torrent in Arabic and English from the notorious Sheikh Abu Hamza.
Meanwhile, more than 2,000 worshippers were peacefully gathering at the nearby Muslim Welfare House. Without pomp, ceremony or police a steady stream of worshippers filed into the building for prayers.
The two mosques were among more than 1,000 contacted this week by the Muslim Council of Britain (MCB) urging greater co- operation between Muslims and the police in the war on terror.
Despite the geographical proximity of the two north London mosques, the sermons that were preached could not have been more different in tone as well as content.
At Finsbury Park, Mr Hamza, who has continued to preach outside the mosque despite its closure more than a year ago, seized the opportunity to inform around a hundred worshippers gathered there that the MCB was "hypocritical" as it was "prostituting itself to the Government".
Standing in the midday sun, he justified his refusal to co-operate with the MCB while condemning the recent spate of arrests under the terrorism acts. "Let's talk about hypocrites," he said. "They call themselves the Muslim Council of Britain. Nobody cares about them. Nobody hears about them. The only people who oblige them are the Government and Tony Blair."
His sermon, in Arabic and English, was full of such phrases as "stupid British soldiers" and "idiot American Yankees".
Referring to the nine arrests made by anti-terror police in London and the South-east this week, he said: "It is immoral and un-Islamic to target people who have no say in the war against Iraq. It's not fair, it's not Islamic and it's not logical."
In this atmosphere of hostility, not a single worshipper wished to discuss the 40-minute sermon. Mr Hamza, however, who was permanently surrounded by his minders, was anxious to expand upon his anger at the MCB letter.
"I was very shocked to receive the letter. This is basically an example of compliance between Tony Blair and the MCB. This is not something I could follow. They are planning together some form of pre-election material.
"It's propaganda and I cannot co-operate with this."
Meanwhile, at the Muslim Welfare House, the fight against terrorism was at the top of the agenda for the two imams who addressed a total of 2,500 people in a double sitting yesterday afternoon.
The mosque's executive director, Fadi Itani, told The Independent: "We had been adopting these lines already, before the arrival of the letter. The last two Friday prayers also dealt with issues of violence and denouncing terrorism. We have always believed that Islam should have no links to violence and terrorism."
He said high-profile speeches such those delivered by Mr Hamza were undoubtedly creating a negative portrait of Muslims within the community.
"It is the same across society," he said. "There is the BNP in the white community and among Muslims there are a very small number of people who do not represent the mainstream but are given a platform to promote themselves."
Amid a growing climate of hostility within the community, Mr Itani described how the recent arrests were greeted with only a feeling of "sadness".
"It is very difficult because Muslim communities are being asked again and again to prove that they are part of this country. That is wrong. The letter is good but it is not just mosques which should be more vigilant."
Among the worshippers there was little sign of the hostility that was found at Finsbury Park mosque, but the issue of growing tension between the authorities and the Muslim community remains a delicate subject.
Ali Khan, a 23-year-old youth education officer, said: "The letter seems a little patronising as it was telling us to do something we do already.
"What we really need is more of a dialogue. People like Abu Hamza do not represent the Muslim community.
"In terms of the arrests, they seem to be happening to ordinary people who are just going about with their lives."Reuse content