( CNN ) -- The mass deaths of thousands of red-winged blackbirds in Arkansas was caused by `` blunt force trauma , '' according to a new report by the Arkansas Game and Fish Commission . Laboratory tests were conducted on 13 of the birds that were part of the group that flew into buildings and died in a neighborhood in Beebe , Arkansas , 40 miles northeast of Little Rock . `` The tests ruled out bacteria , viruses , heavy metals , pesticides and avicides ( chemicals used to kill birds ) as causes of death , '' the commission said in a statement . These results confirmed preliminary tests that were conducted after the incident . The tests revealed hemorrhaging `` consistent with blunt trauma , '' according to the report released Wednesday . `` In most instances , such traumatic injuries in wild birds are due to flying into stationary objects such as trees , houses , windows , power lines , towers , etc . '' Officials say as many as 5,000 birds died in the incident . This incident came several days before another mass death of animals . In that incident , 450 miles south of Beebe , some 500 red-winged blackbirds , starlings and sparrows were found dead . Also that same week , about 50 dead birds were found on a street in Sweden . CNN 's Scott Thompson contributed to this report .
As many as 5,000 birds fell out of the sky in Beebe , Arkansas . Score: 7 In an unrelated case , 500 birds died in a nearby city .