Russia and the US have agreed to coordinate air strikes against Islamist militants in Syria, part of a detailed agreement to reduce the violence there. The plan will begin with a cessation of hostilities from Monday. <br/><br/>Syrian forces will end combat missions in specified opposition-held areas. Russia and the US will then establish a joint centre to combat jihadist groups, including so-called Islamic State (IS). <br/><br/>A Syrian opposition coalition has cautiously welcomed the agreement. <br/>The announcement follows talks in Geneva between US Secretary of State John Kerry and his Russian counterpart, Sergei Lavrov.