The US Secretary of State Mike Pompeo spoke to Ethiopian Prime Minister Abiy Ahmed on Thursday to congratulate him for his recent Nobel Peace Prize win and to discuss domestic and regional issues."They also discussed recent violent protests in Oromia and the need to peacefully address the challenge of ethnic conflict," a statement posted on the State Department website said. Ethiopia has been hit by ethnic violence since Mr Abiy came into office in April 2018.The latest flare-up was sparked by reports that the government was planning to withdraw state-provided bodyguards from influential Oromo activist and media owner Jawar Mohammed. The government however denied the allegation.Some 78 people were killed in the violence which hit parts of Ethiopia last week, Prime Minister Abiy Ahmed's press secretary, Billene Seyoum, said on Thursday.The security forces arrested more than 400 people in connection with the killings and the destruction of properties, she added.Mr Pompeo also asked Mr Abiy to help in the implementation of the South Sudan peace deal, the statement said.