In a major counter-terrorism swoop, British police on Tuesday arrested four young men, suspected of fund-raising and travelling to Pakistan to undergo terrorist training for conducting a suicide bombing campaign in the UK.
The arrests followed pre-planned raids on their addresses early on Tuesday in the Sparkhill area of central English city of Birmingham.
The suspects - three aged 19 and one aged 24 - are suspected of fund-raising in the UK and travelling to train for terrorist purposes in Pakistan.
"Today's arrests were pre-planned and not made in response to any immediate threat to public safety. Officers were unarmed," said a statement from West Midlands Police. The nationalities of the arrested persons were not divulged.
Eight others have already been charged in connection with the investigation, known as Operation Pitsford, the BBC reported.
Seven of those are currently on remand after appearing in court.
Three men were charged with "planning a bombing campaign" and "stating an intention to be a suicide bomber".
Other charges the suspects faced included collecting money for terrorism, travelling to Pakistan for training in bomb making and making a "martyrdom" film.
Detectives have an initial 48 hours to question the four men arrested. Officers must then either charge them, release them, or apply for a warrant to question them further.
West Midlands Counter Terrorism Unit said the arrests were not in response to any immediate threat to public safety.