The UN and aid groups on Thursday scrambled to bring supplies into Ethiopia’s war- and famine-wracked northern Tigray region, which has become largely inaccessible after the latest bout of fighting. UN spokeswoman Eri Kaneko said the situation in Tigray was “volatile and unpredictable” after rebel forces this week retook the regional capital, Mekelle, in a major reversal of fortunes in the eight-month conflict. The American aid agency USAID says some 900,000 people face famine in Tigray — a number likely to grow following the destruction of Tekeze Bridge, an important supply route into the region. “There are no flights or road transportation in or out of the region,” said Ms Kaneko. “We, along with our partners, are assessing access along main roads to several areas to resume aid delivery. Our colleagues say it is urgent to get additional staff and supplies into Tigray.” She described reports of clashes in southern and north-western Tigray amid the rebel counteroffensive, though the situation was calm in Mekelle and other major towns, including Adigrat, Adwa, Aksum and Shire. The International Rescue Committee, an aid group, posted on social media that humanitarians were “devastated” to learn that a bridge and vital supply route on the Tekeze River in Tigray had been “destroyed”. “This means aid efforts will be even more severely hampered amid the continuing conflict,” the group said. Samantha Power, the administrator of USAID and the Joe Biden administration’s top aid official, said other routes into Tigray had been blocked by soldiers and fighting while only one “might be passable”. “Disastrous with up to 900,000 people in famine conditions,” Ms Power posted on Twitter. Tigray’s former rulers, the Tigray People’s Liberation Front, said on Monday they had regained control of Mekelle and Ethiopia's government declared a unilateral ceasefire. People in Mekelle and Shire said incoming Tigrayan fighters were greeted with cheers. The UN said last month that at least 350,000 people in Tigray faced famine and 5.2 million others were in need of aid. after months of war. There have also been reports of widespread rape, civilian killings and other atrocities. likel Abiy Ahmed acknowledged government troops had left Mekelle after months of fighting, but played down the withdrawal, saying the conflict was no longer a priority. Mr Abiy, a Nobel Peace Prize winner, has come under mounting international pressure to bring an end to the fighting. The conflict in Tigray has been challenging for aid workers who have pleaded for better access to the region since fighting began in November, with Ethiopian forces backed by troops from neighbouring Eritrea pursuing Tigrayan rebels. “The violence must now stop and unfettered humanitarian access granted,” a UK foreign office representative said on Thursday. “Eritrean forces should also leave Tigray.” At least a dozen aid workers have been killed, including three humanitarians with the medical charity Doctors Without Borders, whose bodies were discovered last week. The UN Security Council is expected to discuss the crisis on Friday. The UN agency for children on Monday accused Ethiopian government forces of dismantling satellite equipment at its Tigray office and violating international humanitarian law and the immunity of the world body. <br/>