|According to 2008 figures, 1,500 terror-related arrests were made in the UK but two-thirds have been released [EPA]
Nine of the 12 men arrested in police raids a week ago have been charged with conspiracy to cause explosions in Britain and with plotting terrorism offences.
Police said on Monday that the men were arrested on December 20 in what authorities said at the time were counter-terrorism raids essential to protect the public from the threat of attack.
Three of the arrested men were released without charge.
According to a statement issued by West Midlands Police, the remainder will appear at the City of Westminster Magistrates Court later on Monday.
"I have today advised the police that nine men should be charged with conspiracy to cause explosions and with engaging in conduct in preparation for acts of terrorism with the intention of either committing acts of terrorism, or assisting another to commit such acts," said Sue Hemming, head of the Crown Prosecution Service Counter Terrorism Division, in the statement.
Three of the men - aged 24, 26 and 28 - are from the Welsh capital Cardiff. Two others aged 20 and 28 are from London, and four aged 19, 25, 26 and 26 are from Stoke-on-Trent in central England, the police statement said.
At the time of the arrests, the BBC reported that most of the suspects were British but they also included a small number of Bangladeshis.
The police statement said that between October 1 and November 20 the suspects had conspired to cause "explosions of a nature likely to endanger life or cause serious injury to property".
It added that between October and December 20, when the men were arrested, they had been downloading from the internet, researching and discussing potential targets, carrying out reconnaissance and "igniting and testing incendiary material".
The statement did not specify what the potential targets were.
Four suicide bombers killed 52 people on three trains and a bus in London in July 2005.