KIEV, Feb. 21 - Ukraine's State Service of Geology and Deposits has complained about pressure from representatives of iron ore miner PJSC Evraz-Sukha Balka, who have been staging a picket outside the agency for several days, preventing its work and demanding the illegal prolongation of special permits for iron ore extraction.

"We call on law enforcement authorities to take control over the picket of Evraz-Sukha Balka representatives because it is a question of national economic security," the authority said in a statement.