Overview
- Two men were detained after the attack near Huntingdon, and police later released the 35-year-old without charge.
- The remaining suspect, a 32-year-old, is in custody on suspicion of attempted murder.
- Police say they are not treating the incident as terrorism.
- Eleven people were treated in hospital and five have been discharged, while a rail employee who intervened remains in a life-threatening condition.
- Government sources said additional officers will patrol the rail network through at least Tuesday, focusing on major stations.