A British court on Monday ordered nine men charged with plotting bomb attacks against British cities to be held in jail until their next court date in January.
Anti-terror prosecutor Sue Hemming advised that the nine should be charged with "engaging in conduct in preparation for acts of terrorism."
Police have not released details of the threats, but they did say the conspiracy began October 1 and continued until December 20, when the suspects were arrested.
Police arrested 12 terrorism suspects in a series of pre-dawn raids in London, Cardiff and Stoke-on-Trent. Three subsequently were released.
All those arrested were between the ages of 19 and 28. Five are of Bangladeshi origin.
Britain has been on high alert and earlier this year upped its terror threat warning to "severe," the second highest possible level, indicating that a terrorist attack is "highly likely."
In 2005, four suicide bombers killed 52 people on London's subway system.