- Summary- Companies- Air strike appears to be among deadliest of war- U.N. informed Ethiopian govt of site's location -sources- Fighting resumed in August after five-month ceasefireNAIROBI, Oct 5 (Reuters) - More than 50 people were killed in an air strike on Tuesday that hit a school in northern Ethiopia's Tigray region that was sheltering people displaced by conflict between the federal and regional governments, two aid workers and Tigray forces said.But four humanitarian sources, who asked not to be named because they were not authorised to speak to the media, said that the school had been hit, citing eyewitnesses and local administrative officials.The deadliest previous air strike of the war occurred in January, when 59 people were killed at a displaced persons camp in the northwestern town of Dedebit, according to the U.N. human rights office.Last week, another air strike in Adi Daero killed at least six civilians and injured at least a dozen, a doctor and two humanitarian workers said, speaking on condition of anonymity.Ethiopia's government said on Wednesday it had accepted an invitation by the African Union to participate in peace talks this weekend."