A Moroccan soldier serving with the United Nations peacekeeping mission in war-torn Central Africa was killed during an attack at an airfield, the UN said on Friday.

The mission did not say who carried out Thursday's attack at Obo in the southeast of the country, AFP said.

"A blue helmet from the Moroccan contingent... died after an attack on Thursday morning at the Obo aerodrome while he was protecting the aerodrome perimeter for a landing, with other members of his continent," said the UN force in Central Africa (MINUSCA).

The 14,000-strong peacekeeping force has been deployed since 2014 in the country which is wracked by civil war.