Nine men have been remanded in custody charged with conspiracy to cause explosions in the UK and other terrorism offences.
Chief magistrate Howard Riddle remanded them to appear at the Old Bailey on January 14.
The suspects were arrested a week ago during a series of dawn raids by counter-terrorism officers.
In all 12 men were held during the raids by unarmed police on December 20 in London, Cardiff, Stoke-on-Trent and Birmingham. Two men from Cardiff and one from London were later released without charge.
The remaining nine suspects were charged on Sunday night with conspiring to cause an explosion or explosions in the UK "of a nature likely to endanger life or cause serious injury to property" between October 1 and November 20 this year.
They are also accused of engaging in conduct in preparation for acts of terrorism between October 1 and December 20, including by downloading and researching materials and methods; carrying out reconnaissance and agreeing potential targets, and igniting and testing incendiary material.