Police are calling for peace after being attacked Monday morning by groups of nationalist protesters throwing Molotov cocktails and other objects at police vehicles at an Easter Rising parade in Londonderry, Ireland. “Our officers have come under attack in Creggan with petrol bombs and other objects thrown at their vehicle while in attendance at an un-notified Easter parade,” the Police Service of Northern Ireland (PSNI) said in a statement. “No injuries have been reported at this time. We would appeal for calm.” Local authorities have already been expecting a violent week—U.S. President Joe Biden’s arrival in Ireland tomorrow to celebrate the Good Friday Agreement is expected to draw protests from the agreement’s dissenters. Police already thwarted an alleged planned terror attack by the New IRA, an Irish republican dissident group, on Sunday.