Police have made a sixth arrest in connection with Friday's (15 September) London terror attack at Parsons Green Tube station. A 17-year-old boy was detained just after midnight on Thursday 21 September in Thornton Heath, south London, after officers carried out a search warrant.

He was arrested under section 41 of the Terrorism Act. It means six people have now been arrested by anti-terror police in connection with the Parsons Green attack, which saw a crude home-made bomb left on a London Underground train.

The device is understood to have failed to properly detonate but still left 30 passengers injured.

Thursday's arrest comes after three men – aged 25, 30 and 48 – were detained in Newport, Wales, on Tuesday night and Wednesday morning.

An 18-year-old was arrested in Dover on Saturday, while the sixth man, Yahyah Farroukh, 21, was detained in Hounslow, west London, on the same day. All six remain in custody.

Commander Dean Haydon, head of the Met Counter Terrorism Command, said: "This continues to be a fast-moving investigation. A significant amount of activity has taken place since the attack on Friday.

"We now have six males in custody and searches are continuing at five addresses. Detectives are carrying out extensive inquiries to determine the full facts behind the attack.

"We anticipate that the searches will take some days to complete and may cause further disruption. However, it is important that we continue with these searches and I'd like to thank all those affected for their support, patience and cooperation.

"As police and our partners do all we can to confront the threat, public vigilance remains as vital as ever.

"We urge the public to report any suspicious activity to the police by calling us, in confidence, on 0800 789 321, or in an emergency by dialling 999.

"We are asking the public to look out for anything that seems out of place, unusual or just doesn't seem to fit in with day-to-day life. It may be nothing, but if you see or hear anything that could be terrorist-related, trust your instincts, then act, and call us."

Parsons Green bag explosion Tube
The Lidl bag which witnesses say exploded on a London Underground train at Parsons Green station Twitter/Rigs