By Simon Marks Ethiopia accused Eritrea of sending troops into its territory and demanded their immediate withdrawal as tensions escalate between the two countries amid renewed conflict in the Horn of Africa nation.

“All foreign military forces operating within our sovereign territory must withdraw immediately,” Enatalem Melese, Minister of the Government Communication Service, told Bloomberg. “In particular, Eritrean forces operating in Tigray must leave Ethiopian territory without delay.”Renewed fighting erupted in Ethiopia last month, four years after it signed a peace deal with the Tigray People’s Liberation Front, ending a two-year war that killed more than half a million people. The TPLF has formed an alliance with other rebel groups to take on the government and has allied with Eritrea. The conflict risks conflagration in the wider region, with civil war in neighboring Sudan ongoing.

Eritrean Information Minister Yemane Gebremeskel didn’t respond to questions about Ethiopia’s allegation. Instead, he accused Ethiopia of laying the groundwork for a war aimed at seizing the strategic Red Sea port of Assab, saying Addis Ababa is seeking to portray its long-standing ambition for sea access as an act of self-defense.

“The Ethiopian regime’s overarching strategy in the past months has revolved around re-packaging its three-year old agenda of war and aggression against Eritrea in ‘self-defense’ terms,” he said. “The final destination is Assab. This is the backdrop of all the accusations.”