The United Nations is calling on Gambia to spare all additional prisoners on death row, after authorities in the West African country executed nine people.

The U.N. special envoy on extrajudicial, summary or arbitrary executions, Christof Heyns, strongly condemned Gambia's action in a statement Tuesday and called for “a halt to further executions.”

Heyns said the executions are a “major step backwards for the country,” and expressed concern that those put to death did not receive due process during their trials.

The Gambian government said Monday that nine death row prisoners, including one woman, had been executed by firing squad the night before.

Amnesty International had reported the executions earlier, saying they took place on Thursday evening.

Gambian President Yahya Jammeh said recently that all death sentences in the country will be carried out by mid-September. Another 39 prisoners are believed to be on Gambia's death row.

The African Union, European Union and former colonial power Britain have called on the president to renounce his plans.

EU foreign policy chief Catherine Ashton warned Gambia that the 27-nation bloc will consider what she called an “appropriate” response to the executions.

Gambia had gone 27 years without an execution until this past week.