African and European nations attempted on Monday to initiate mediation in Ethiopia's escalating internal conflict, two days after rocket strikes on Eritrea's capital highlighted risks that fighting could spread. Hundreds have died, 25,000 refugees have fled to Sudan and there have been reports of atrocities since Prime Minister Abiy Ahmed ordered air strikes and a ground offensive on November 4 against Tigray's rulers after he accused them of attacking a federal military base. The war has spilled into neighbouring Eritrea and rocked the wider Horn of Africa, diplomats said. But Africa's youngest leader, who won a Nobel Peace Prize last year, has so far resisted pressure for talks. His government denied Uganda was shaping up as a mediator even though President Yoweri Museveni met Ethiopia's foreign minister and appealed for negotiations. "The claim of mediation in Uganda is NOT true," Mr Abiy's special task force for Tigray said on Twitter. Ugandan President Yoweri Museveni later deleted a tweet calling for negotiations to stop the conflict “lest it leads to unnecessary loss of lives and cripples the economy". An Ethiopian official said Mr Demeke made clear negotiations weren't an immediate possibility. "We don't need mediation until we bring ringleaders to court," Redwan Hussein, spokesman for a crisis committee set up to respond to hostilities in Tigray, told reporters in Addis Ababa. "Any mediation would incentivise impunity and unruliness." The Tigray flare-up could jeopardise the recent opening up of Ethiopia's economy, stir ethnic bloodshed elsewhere around Africa's second most populous nation, and tarnish the reputation of Mr Abiy, 44, who won his Nobel for peace with Eritrea. The Tigray People's Liberation Front (TPLF), which governs the region of 5 million people, has accused Eritrea of sending tanks and soldiers over the border against it. Asmara denies that. Tigray forces fired rockets into Eritrea at the weekend. Ethiopia's task force said federal troops had "liberated" the town of Alamata from the TPLF in south Tigray after saying last week they had seized the West. Nigeria's former president Olusegun Obasanjo travelled to Addis Ababa on Monday in an attempt to push for talks. "The door is closed but we have to keep being vocal. Just because he (Abiy) doesn't want it (mediation), we are not going to keep quiet," the diplomat told Reuters.