pbr Police working on the Raoul Moat inquiry have arrested another three men on suspicion of assisting an offender.br ppbr The men, aged 27, 34 and 45, were arrested at two addresses in Newcastle and one in Wallsend.br ppbr A total of 13 arrests have now been made in relation to the Moat inquiry but a Northumbria Police spokesman said: "At this stage the investigation is still ongoing and further arrests can't be ruled out."br ppbr During Prime Minister's Questions, David Cameron said that there should be no public sympathy for gunman Raoul Moat, describing him as a "callous murderer".br ppbr Mr Cameron told the Commons that any sympathy should be reserved for Moat's victims.br ppbr "It is absolutely clear that Raoul Moat was a callous murderer, full stop, end of story," he told MPs, adding: "I cannot understand any wave, however small, of public sympathy for this man. There should be sympathy for his victims and the havoc he wreaked in that community."br ppbr One of Moat's victims, PC David Rathband, has spoken about the moment the gunman approached his car in East Denton, Newcastle, in the early hours of July 4. He said: "I looked into his eyes and I saw nothing - no emotion."br ppbr Moat shot and killed himself after a standoff with police in the Rothbury area last week. Police had been searching for him for days after he seriously injured his ex-girlfriend and her new partner in Birtley, Gateshead.