The British Home Secretary Amber Rudd says, the man who carried out a suicide attack in Manchester has not acted alone. <br/><br/>Salman Abedi killed 22 and injured 64 when he blew himself up at the Manchester Arena on Monday night. <br/><br/>Police arrested three more men in Manchester today, bringing the total number to four. Abedi's 23-year-old brother was arrested yesterday.<br/><br/>The Palace of Westminster has been closed to the public following police advice, and will not re-open until further notice. <br/><br/>Defence sources said, changing the Guard ceremony at Buckingham Palace has been cancelled today to redeploy police officers.