The terrorist Khalid Masood was not a “lone wolf” and others had played a key part in indoctrinating him and helping to carry out Wednesday’s deadly attacks in London, security officials believe.

The disclosure that the British-born Muslim convert was likely to have been part of a wider conspiracy came as armed police detained 11 people in raids across the country with two of the arrests, including that of a woman, described as “significant” in the investigation.

Three cars were also taken away for forensic examination. Police are still hunting associates of Masood who are believed to be linked to the Westminster attack.

Khalid Masood: London terror attacker ‘was not lone wolf’ but part ...