Two brothers accused of plotting an Isis-style bomb attack in London have been released on police bail. The suspects – aged 19 and 20 – were arrested on Thursday (9 September) in north-west London as part of a pre-planned operation that included searching homes in London and the Thames Valley area.

Their plan is believed to be the biggest one police have dismantled in two years and reportedly involved steps to build a bomb. The younger suspect was arrested on suspicion of preparation of terrorist acts and the older one was detained on suspicion of funding terrorism and failure to disclose information regarding an act of terrorism. The 20-year-old is also suspected of preparing terrorist acts in relation to a separate investigation by the South East Counter Terrorism Unit.

The pair were bailed on Friday (9 September) until early November pending further enquiries as searches continue at address related to the investigation. A third man, a 19-year-old Iraqi who it is believed knew the brothers, was arrested in south-east London on suspicion of a religiously aggravated offence in relation to a separate matter. He remains in police custody.

In a separate investigation, four men were charged on the same day with preparing to commit acts of terrorism after raids in Birmingham and Stoke-on-Trent after West Midlands counter terrorism officers arrested them in late August.

Naweed Ali, 28, of Evelyn Road, Sparkhill; Khobaib Hussain, 24, also of Evelyn Road, Sparkhill; Mohibur Rahman, 31, of High Lane, Stoke-on-Trent; Tahir Aziz, 37, of Wulstan Road, Stoke-on-Trent, are due to appear at Westminster Magistrates Court on Friday (9 September).