The Bishop of Reading has spoken of her sadness over the death of three people in a stabbing attack in Reading on Saturday night. 

Three more were seriously injured in the attack in Forbury Gardens at about 19:00 BST.  A 25-year-old man was detained at the scene and arrested for murder after reportedly being tackled by a lone police officer.  Early reports describe him as a Libyan asylum seeker. 

Early on Sunday, the investigation was upgraded to a counterterrorism enquiry, with all indications pointing to the incident being a terror attack.

Video footage, filmed by a bystander and posted on social media, appeared to show police giving CPR to several victims with knife wounds.

Police have asked witnesses to come forward, and to provide authorities with video footage of the attack, although they pleaded that bystanders do not share the videos with others or online.

The Bishop of Reading, the Rt Rev Olivia Graham, responded on Twitter, saying she was "horrified" by the stabbings. 

"Prayers tonight for victims and their families and all emergency service personnel involved," she wrote. 

Rev Chris Russell, vicar of St Laurence, Reading, which lies just within the police cordon, said: "My thoughts are with all of those affected by the appalling incident in Reading and my thanks to the emergency services on the scene...come Holy Spirit." 

Prime Minister Boris Johnson said his "thoughts are with all of those affected by the appalling incident in Reading".

"My thanks to the emergency services on the scene," he added.