Via Daily Mail:
Twelve men were arrested early this morning in a major national counter-terrorism operation, police said today.
The men - five from Cardiff, four from Stoke-on-Trent and three from London - were detained on suspicion of the commission, preparation or instigation of an act of terrorism in the UK.
The suspects, aged between 17 and 28, were detained by unarmed officers at approximately 5am.
It is understood that the plans for the alleged attacks were at an advanced stage.