In US, three women have been shot dead and a man critically injured at a shopping centre in Burlington. <br/><br/>The shooting occurred at the Cascade Mall in Washington. Police have released a picture of the suspected gunman, who fled the scene armed with a rifle. <br/><br/>The Mall and nearby shops have been evacuated and police have asked the public to stay away. Washington State Patrol spokesman Mark Francis said on Twitter that the gunman had left the scene before police arrived and the motive for the attack is unclear.