Zambia’s government filed notification of plans to take over Vedanta Resources’s domestic copper assets, President Edgar Lungu said. The move marks an escalation in tension between the government and mine owners, after Lungu last week threatened to “divorce” Vedanta and Glencore, two of the biggest employers in Africa’s second-largest copper producer. Relations have been simmering after the state earlier this year increased royalties and unveiled a plan to overhaul the value-added tax system.