In a statement, the EU said humanitarian workers should not be a target and described the incident as a senseless violence and great violation of all humanitarian principles, Xinhua reported.
"Right now, our thoughts are with families, friends and organisations of all those affected and the most vulnerable people aid workers strive to help in Nigeria," said Christos Stylianides, Commissioner for Humanitarian Aid and Crisis Management.
Meanwhile, Nigerian president Muhammadu Buhari also condemned an attack by suspected Boko Haram fighters in the country's northeastern town of Rann, in which three aid workers were killed late Thursday.
In a statement, Buhari said the attack, more than ever, showed Boko Haram terrorists as "godless, brutish, and utterly to be despised."
Buhari said such cowardly attacks can only bolster the determination of the government to bring the Boko Haram terrorists to a decisive end, in the shortest possible time.
Earlier on Friday, the United Nations confirmed the killing of the three aid workers and said a fourth aid worker was feared killed and another likely abducted during the attack. A local nurse was also injured.
All the aid workers affected by the attack were Nigerian nationals, according to Samantha Newport, a UN spokeswoman in Nigeria.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
