Two of the six men arrested over last week's London subway bombing were released without charge Thursday, British police said. Four others remained in custody.
One of those released is a 21-year-old, originally from Syria, detained outside a fast-food restaurant in west London on Saturday, a day after the rush hour attack on a subway train. The other is a 48-year-old man arrested Wednesday in Newport, Wales.
Thirty people were injured when a homemade bomb — placed inside a bucket wrapped in a supermarket bag — partly detonated on a train stopped at London's Parsons Green station.
The attack sparked a manhunt for the perpetrators and prompted officials to briefly raise the national terrorism threat to the highest level.
The suspects still being held include an 18-year-old from Iraq detained at the English Channel port of Dover on Saturday.
Two men aged 25 and 30 arrested in Newport earlier this week remained in custody, as did a 17-year-old detained early Thursday in south London.
None of the suspects has been charged.
