Ethiopian troops are now in “full control” of Mekelle, the capital of the northern region of Tigray, the prime minister, Abiy Ahmed, said on Saturday evening. “With full command of the regional capital, this marks the completion of the Ethiopian National Forces’ last phase … The main operation is successfully concluded,” Abiy said. There was no immediate confirmation of the claim, nor reaction from the Tigray People’s Liberation Front (TPLF), the ruling party in the restive region. However, if confirmed, the news would probably mean the end of the confrontation between TPLF forces and federal troops on the battlefield. The advance on Mekelle came almost a week after Abiy told the TPLF leadership to surrender or face an assault on their stronghold. The capture of Mekelle would be seen as a personal triumph for the 44-year-old prime minister and would bolster his position as a national leader. However, experts have said federal forces may face a lengthy insurgency in the region. With communications to Tigray cut off, it is difficult to confirm information and conflicting claims. In recent days, Ethiopian federal forces have reinforced their positions in a rough ring around Mekelle, at a distance of 20-40km. Fighting over the last week has included clashes on ridge lines, mountain passes and key road junctions, with heavy casualties reported. The advance on Saturday appears to have been rapid, with limited resistance. Some experts speculated that the TPLF may have abandoned the city. From 10am, Ethiopian federal forces reportedly used heavy artillery to shell the outskirts of the city of 500,000. Later in the day, the movement of tanks was reported around Mekelle’s airport. Debretsion Gebremichael, the leader of the TPLF, told Reuters in text messages the city was under “heavy bombardment”. Aid workers in Mekelle said explosions had been seen and heard, though it was unclear whether artillery, tanks or airstrikes were responsible. Billene Seyoum, a spokesperson for the prime minister’s office, denied the claim, saying “the Ethiopian National Defence Forces do not have a mission to bombard its own city and people”. Seyoum added: “[Mekelle] remains one of Ethiopia’s key cities and the efforts to bring to justice the criminal clique will not entail discriminatory ‘bombardment’ as alluded by TPLF and their propagandists.” In his statement, issued at about 7pm local time, Abiy said that the military part of the “law enforcement operation” undertaken against the TPLF was over and the police would now seek to apprehend the “TPLF criminals and bring them to a court of law”. In his statement, Abiy thanked the “people of Tigray” for their cooperation with federal forces. Earlier this week, military officials warned of “no mercy” if residents of Mekelle did not distance themselves from the TPLF. Abiy launched the operation three weeks ago in Tigray to “enforce the rule of law in the region and the country” and promised that civilians would be protected. Earlier in the week the state-affiliated Ethiopian Broadcasting Corporation said the federal forces had identified key TPLF hideouts across Mekelle, including an auditorium and a museum. Government planes have dropped leaflets on the city warning inhabitants to stay out of harm’s way. Some residents fled, with satellite images revealing lengthy queues of vehicles at petrol stations earlier in the week. Analysts are sceptical that the TPLF high command, who withdrew to Tigray earlier this year as tensions with central government escalated, had stayed in Mekelle, but is likely to have scattered into remote hiding places. Abiy met envoys sent by the African Union to mediate an end to the crisis on Friday, but they have not been permitted to travel to meet representatives of the TPLF and gave no sign that the national government was contemplating a ceasefire or negotiations. The TPLF renewed a call for talks on Friday. “Tigray … is ravaged by war … an immediate cessation [of hostilities] is of paramount importance”, Getachew Reda, a political adviser to the leader of the TPLF, said. Ethiopian officials have made clear they do not recognise the TPLF as a legitimate negotiating partner. A statement from Abiy’s office after a meeting with the envoys said: “Failure to enforce the rule of law [in Tigray] would nurture a culture of impunity in [Ethiopia] with devastating consequences.” Abiy launched the military campaign on 4 November, accusing the TPLF of attacking federal military camps in Tigray and seeking to destabilise the country. The Ethiopian human rights commission has also blamed TPLF-linked militia for a massacre in Tigray of many hundreds of labourers from the neighbouring Amhara region. The TPLF denies the charges, saying they are concocted by the government as a pretext to launch a military operation to end its rule in Tigray. The party says it is defending its legitimate rights under Ethiopia’s devolved constitutional system. Ethiopian authorities have made some concessions to international pressure, offering to set up a humanitarian corridor to allow aid to reach the tens of thousands who have been displaced by fighting, and much larger numbers who are suffering from the disruption of supplies of food, fuel and medicine. Western diplomats and humanitarian officials said the promises were welcome but that nothing had changed on the ground. “It is encouraging to hear these kinds of things but until there is actual movement to allow aid into Tigray then they don’t mean a lot,” one said. “There are serious issues with the idea of setting up a humanitarian corridor under government control.” Last week the UN said shortages were “very critical” in Tigray, with fuel and cash running out.