The charity Doctors Without Borders has expressed “shock and outrage” over the killing of three colleagues in northern Ethiopia, the latest aid worker deaths in the war-torn Tigray region. The medical group said in a statement that two Ethiopian employees and one Spanish citizen were found dead on Friday, a day after contact was lost with the team during a humanitarian mission. “No words can truly convey all our sadness, shock and outrage against this horrific attack,” the group said in a statement. “We condemn this attack on our colleagues in the strongest possible terms and will be relentless in understanding what happened.” The organisation identified the dead aid workers as Maria Hernandez, the group’s emergency co-ordinator, assistant co-ordinator Yohannes Halefom Reda and driver Tedros Gebremariam Gebremichael. Their bodies were discovered a few metres from the vehicle they had been using, added the statement, without indicating where the killings took place. A spokesman for Ethiopia's Prime Minister Abiy Ahmed did not reply to a request for comment. UN spokesman Stephane Dujarric condemned the targeted killings of aid workers. “We fear the goal of scaring away humanitarians,” said Mr Dujarric. “It denies men, women and children who need help, the help that they need.” The attack comes amid some of the fiercest clashes in Tigray since fighting began in November, when Ethiopian forces, backed by neighbouring Eritrea and allied militias, began a campaign against the Tigray People's Liberation Front. At least a dozen aid workers have been reported as killed during the conflict in Tigray, with humanitarian agencies routinely denied access to the region. Ethiopia’s military this week acknowledged carrying out an air strike on a busy market in the Tigrayan village of Togoga that reportedly left several dozen civilians dead. The military claimed it was carrying out an attack on enemy fighters. Mr Dujarric said UN field teams were struggling to gain access to the area to investigate the air strike and assist civilians due to ongoing fighting. “It is unacceptable on so many levels,” he told reporters on Friday. We need to get in there to assess the situation. We need to get access to those people who need help.”