Northern Ireland has been hit by a second night of violence in Belfast and other towns. The first clashes, on Monday, were sparked by the annual Orange Order marches, which commemorate the 17th century victory of Protestant forces over Catholics. But police said the continuing unrest appeared to be stage-managed, with rioters bussed-in to attack officers.Northern Ireland has been relatively peaceful since a deal in 1998 ended years of the IRA’s violent campaign against British rule. But Republican splinter groups are blamed for killing two British soldiers and a policeman in March and other isolated attacks. Sinn Fein said dissident Republican criminal gangs had orchestrated the latest trouble.