Flights over Bulgaria could increase by 10-15% after the closure of Eastern Ukrainian airspace, Europe's organization for safety of air traffic estimates.

However, Bulgarian private national channel bTV argues the figure could rise, as many airlines have decided to avoid passing via Ukraine in the near future.

Ivan Dyaksov, Deputy Director General of the Bulgarian Air Traffic Services Authority (BULATSA), told the channel certain unrest-torn zones of Ukraine "should have been closed earlier," as no-one could ensure flight safety when fighting is ongoing.

Between 150 and 160 flights reach Europe from the Middle East using Ukraine's airspace.

Dyaksov, who manages operating activities in the state-owned enterprise, believes planes will avoid Ukraine "for a long time, as long as the conflict continues".

He added real consequences of air-traffic reshuffle are to be seen next week.

Most carriers now prefer to go around Ukraine after a Malaysia Airlines' Boeing 777 crashed in the eastern part of the country killing all 298 on board.

Both Kiev and pro-Russian rebels mutually accuse each other of having downed the plane.