CNN 's Diana Magnay , Yesim Comert , Sarah Jones and Michael Martinez contributed to this story . NEW : The death toll rises to 570 , officials say , with about 2,555 people injured . -- A man in the northern city of Aleppo is killed by a mortar shell as he tries to flee his home after regime forces launched an offensive against rebels there. Britain pledges emergency tents for more than 5,500 people .
NEW : The death toll rises to 570 , officials say , with about 2,555 people injured . -- A man in the northern city of Aleppo is killed by a mortar shell as he tries to flee his home after regime forces launched an offensive against rebels there. Britain pledges emergency tents for more than 5,500 people .