A Zambian court on Wednesday refused to drop treason charges against opposition leader Hakainde Hichilema, instead adding a new indictment that accuses him of seeking to establish himself as president in the Western Province capital of Mongu.

The government said that Hichilema, a prominent businessman and leader in the United Party for National Development (UPND), and Wallace Chakwa – one of five others initially charged in the treason case – conspired to have Hichilema “accorded the status” of president, the Lusaka Times said.

The new claim follows Zambia’s charge that Hichilema, in insulting President Edgar Lungu and blocking his motorcade on April 8, committed a treasonous act that was calculated to usurp state authority.

Hichilema pleaded not guilty to the charges relating to the motorcade incident.

The incident has increased tensions among UPND members who have been warned not to publicly protest or rally by police. Hichilema’s arrest also comes as other opposition party leaders say they feel threatened and intimated, including Saviour Chishimba of the United Progressive People party.

The chaotic midnight arrest and detention of Hichilema has been widely condemned by the international community, including the European Union and the United States. The U.S. Embassy in Lusaka appealed for a dialogue between the UPND and Lungu’s government, and urged calm amid the heightened political tensions.

Human rights organizations including Amnesty International have called for the treason charges to be dropped. “These charges are a massive conflation of what is essentially a traffic control issue; it should not be labeled treason, said Deprose Muchena, the organization’s regional director for southern Africa, in a statement issued Wednesday ahead of the hearing.

Image: UPND