Poland expresses regret after rioters attack Russian Embassy in Warsaw . The Polish Foreign Ministry said it was "shocked and deeply concerned" by the incident. Russian media say protesters threw fireworks at Polish Embassy in apparent retaliation . Poland declared independence on November 11 , 1918 , at the end of World War I .
Poland expresses regret after rioters attack Russian Embassy in Warsaw . Police say participants in an Independence Day march set a guard booth on fire . Russian media say protesters threw fireworks at Polish Embassy in apparent retaliation . Poland declared independence on November 11 , 1918 , at the end of World War I .