London bomb suspect arrested at Dover

An 18-year-old man in connection with the Parsons Green terror attack has been arrested.

His house in Dover has been evacuated and officers are searching it in connection with Friday’s London Tube bombing.

The evacuation started at 14.40, with residents in the surrounding areas also being removed as a “precautionary measure”.

A cordon has been put in place 100 metres around the property. Both Met and Surrey police carry out the search.

"We have made a significant arrest in our investigation this morning," Deputy Assistant Police Commissioner Neil Basu said.

Basu warned that the investigation was ongoing and the terrorist threat level remains at "critical," indicating that a government task force, including the security services, believes another attack is imminent.

Basu's comments suggested that other dangerous suspects may still be at large.

The 18-year-old suspect hasn't been charged or identified. Police say he will be brought to a south London police station for more questioning. Police haven't said if he is suspected of planting the bomb or if he played a supporting role in a possible plot.

Police are combing through closed-circuit TV images and have extensively studied the remains of the device without giving details about it. But images from inside the subway car after the blast showed that the device was contained in a bucket with wires hanging out of it and that it was concealed in a plastic shopping bag.

Officials have hinted there may be more than one person involved, but haven't released details in what is termed an ongoing and covert inquiry.