This map shows how the Parsons Green terror investigation goes far beyond a few guys in London

Map of the Parsons Green arrests.

Map of the Parsons Green arrests.
Google Maps/Business Insider

Detectives pursuing those responsible for the Parsons Green bomb attack on the London Underground last week arrested another man in the early hours of Thursday morning, taking the total number of arrests to six.

All suspects – five men and a 17-year-old boy – remain in custody and are being questioned by counter-terror officers after a makeshift explosive went off on a District Line train in west London last Friday, injuring 30 people.

Yahyah Farroukh, a 21-year-old Syrian refugee who worked in a chicken shop, is the only person to have been identified.

Here are the details of the six arrests, which began the day after the attack on September 15.

September 16, 7:50 a.m., Port of Dover: Kent Police arrest an 18-year-old man. September 16, 11:50 p.m., Hounslow, west London: Met Police arrest 21-year-old Yahyah Farroukh. September 19, 7:00 p.m., Newport, South Wales: Met Police and Gwent Police arrest a 25-year-old man. September 20, 5:10 a.m., Newport, South Wales: Met Police and Gwent Police arrest a 48-year-old man. September 20, 5:10 a.m., Newport, South Wales: Met Police and Gwent Police arrest a 30-year-old man at the same address. September 21, 12:05 a.m., Thornton Heath, south London: Metropolitan Police arrest a 17-year-old boy.

All of the suspects have been taken to the same location, an unspecified police station in south London, where they are being questioned.

Police have repeatedly declined to give a “blow by blow” commentary on their investigation. But after the first two arrests, the UK’s terror threat level was reduced from “critical” to “severe,” suggesting that the possibility of an immediate follow-up attack from the same group had diminished.

Officers’ focus has so far been on the south of the country, stretching from Dover in the east to Newport, 186 miles away in Wales. ISIS has claimed responsibility for the attack, though there is little evidence to suggest their direct involvement.

The most activity has been around London, where officers have searched the chicken shops where Farroukh worked, a residential property just outside Heathrow Airport, and a foster home just across the border between Greater London and Surrey. Media reports have suggested the bomb was made in the latter location.

None of those detained has been charged with any crime, meaning police have given little away about what exactly they believe each suspect’s role could have been.

Under British counter-terror laws, police are allowed to detain terror suspects without charge for up to 14 days, meaning it could be the end of the month before any allegations against the men are spelled out.