By James Tozer
Last updated at 5:46 PM on 26th August 2008

A white Muslim convert has been arrested in connection with threats to kill the Prime Minister which were posted on an extremist Islamic website.

The latest suspect, named locally as Mohammed Ali, was seized in a dawn raid at his flat above a butcher’s shop in Blackburn, Lancashire.

His arrest came ten days after three other men were held by anti-terror police over threats to assassinate Gordon Brown and his predecessor, Tony Blair.

Enlarge Dawn raid: A policeman stands outside the house where a fourth man has been arrested over terror offences

They include two brothers arrested as they were about to board a flight to Finland at Manchester Airport.

A third was taken into custody shortly afterwards at a warehouse in Accrington.

Police today swooped on the 24-year-old man, who had earlier spoken of how he had fallen out with the two brothers because their views were ‘too extreme’.

Mr Ali, who is thought to have converted to Islam about four years ago, was last night being questioned in relation to the assassination threats.

Anti-terror teams have spent months investigating the warnings on a recognised jihadi website in January by a group calling itself ‘Al Qaeda in Britain’.

The statement also demanded the withdrawal of British forces from Iraq and Afghanistan and the release of Muslim prisoners from Belmarsh high-security prison in London.

Postings to the site and others like it are regularly monitored by the security services over fears that they are used to radicalise and recruit young British Muslims.

However police sources have stressed that there is no evidence that there was any active plot.


Terror plot: Gordon Brown and his wife Sarah at the Beijing Olympics

Anti-terrorist officers are still holding the three other suspects, aged 21, 22 and 23, who were arrested on August 14.

They have also travelled to Scandinavia as part of their investigations.

The latest arrest was made when police forced their way into a rented flat above a butcher’s shop in a mainly Muslim area of Blackburn at about 6.40am today.

Mr Ali had previously spoken to reporters about his links with the arrested brothers, who lived nearby.

‘I have been in their house and we were friends, but we fell out because our views differed,’ he said.

‘I follow the Koran but their views were too extreme and we no longer speak.’

He added that as his fingerprints would be at the brothers’ home, he would not be surprised if he too was arrested.

Today a friend, a 25-year-old businessman, said Mr Ali was a regular worshipper at the local mosque and did not support extremist opinions.

‘He did hang around with the two brothers but didn’t share their views,’ he said.

‘He told me he said they were too extreme and he just followed the Muslim religion and the prophet.

‘I’m not surprised that there has been another arrest. I’ve seen plain-clothed police hanging around in cars for a few weeks now.’

Senior members of the area’s Muslim community spoke of their shock at the first three arrests, saying all were devoutly religious men and had travelled abroad - including to Iceland - to lead prayers and teach their faith.

Detectives have until later this week to continue holding the trio.

Justice Secretary Jack Straw, who is the local MP, is being kept informed about the investigation, and police have been handing out leaflets to local residents asking them to remain patient while they carry out their inquiries.