Ukrainian Infrastructure Minister Vladyslav Krykliy announced the death toll on his Facebook page, and said an investigation is underway.
He said the An-12 plane was carrying seven crew members and one passenger Friday morning when it sought to make an emergency landing for lack of fuel.
The regional emergency service said in a statement that emergency workers rescued three people from the wreckage who were hospitalized with injuries.
The Infrastructure Ministry said the plane was traveling from Vigo in northwestern Spain to Istanbul and planned a refuelling stop in Lviv. Ukrainian news reports said it crashed 1.5 kilometers (less than a mile) from the runway.
Spanish airport operator AENA confirmed that the cargo flight UKL4050 operated by Ukraine Air Alliance had departed from Vigo airport just after midnight on Friday. The cargo plane had arrived in Vigo a day earlier from Toulouse, France.
The Ministry of Foreign Affairs said there was no initial indication that any of the victims or survivors was Spanish.