MAIDUGURI, Nigeria

The United Nations on Saturday condemned the murder of four aids workers this week by the Boko Haram terrorist group in northeast Nigeria.

UN Humanitarian Coordinator in Nigeria Edward Kallon said the international community was saddened by the killing of the aid workers who were abducted by terrorists in July on their way to a remote community in the northeast to provide humanitarian support to victims of Boko Haram violence.

He said the incident could jeopardize access to humanitarian support in the region.

"I am deeply saddened and outrage by the news of the tragic killing of four aid workers who were held captive by the Armed group for almost five months," said Kallon in a statement.

The four men were among the six humanitarian workers, including a driver and a woman, who was kidnapped by the terror group July 26 in Damasak near the Lake Chad region in Borno State.

One of the aid workers was reportedly executed in late September while the woman, identified as Grace Taku, is still held by the terrorists.

Kallon demanded her immediate release.

"I plead for the immediate release of Grace Taku, the only woman who was in the team, and whose whereabouts remain unknown," he said.