Three men who were arrested over the Parsons Green Tube attack have been released with no further action, the Metropolitan Police has said.
Of the seven men arrested in total over the bombing in London on 15 September, one has been charged with attempted murder and the remaining six released.
Ahmed Hassan, 18, of Sunbury, Surrey, was remanded in custody after appearing in court last week.
A bomb partially exploded on a Tube train in rush hour, injuring 30 people.
Two of the released men, aged 25 and 30, were arrested in Newport, south Wales on 19 and 20 September respectively.
The third released man was arrested in Cardiff on Monday.
Officers are continuing to search one property in Cardiff as part of the investigation led by the Met’s Counter Terrorism Command, police said.