LONDON (Reuters) - Three men have been arrested in northern England as part of investigations into death threats against Prime Minister Gordon Brown and his predecessor Tony Blair, the BBC said on Friday.
It said two men were arrested last week at Manchester airport about to board a flight to Finland, while the third was arrested elsewhere in the region.
Lancashire police confirmed three arrests had been made under anti-terrorism laws but declined to give any more details.
"There is an ongoing investigation surrounding the three men arrested on August 14, 2008, and they remain in custody," a spokesman said. "Therefore, we are not in a position to comment any further."
A spokeswoman at Brown's Downing Street office said: "We don't comment on security matters." Brown is in Beijing for the closing ceremony of the Olympic Games on Sunday.
The BBC said the police investigations concerned threats posted on a Jihadi website in January by a group calling itself al-Qaeda in Britain to mount suicide attacks on Brown and Blair unless Britain withdrew its troops from Iraq and Afghanistan.
It also demanded the release of Muslims imprisoned in Britain.
The posting appeared on www.alekhlaas.net, a site which hosts a catalogue of Islamist messages, musings and writings and has been visited by more than 17 million people.
A security source told Reuters at the time it was regarded as typical militant background noise.
Britain has seen a marked increase in attacks by Islamist militants since it joined the United States in invading Afghanistan and Iraq in the wake of the September 11, 2001 attacks on New York and Washington.
In July 2005, Islamist suicide bombers killed 52 people in coordinated attacks on London's transport system. Several other alleged plots have failed or been uncovered by police, including attempted car bombings in London and Glasgow last June.
Reporting by Avril Ormsby, writing by Jeremy Lovell, editing by Robert Hart