BAMAKO, Mali (AP) — A U.N. peacekeeping helicopter crashed Wednesday in the desert in northern Mali and two German peacekeepers were killed, U.N. officials said.

U.N. deputy spokesman Farhan Haq said the crash took place south of Tabankort in Mali's northern Gao region. He said officials were still working to verify details of the crash, including its cause and possible casualties.

"Preliminary indications show there was a technical failure. Investigations are opened to determine the exact circumstances of the crash," said a statement by the U.N. mission in Mali. "The helicopter had two peacekeepers on board who, unfortunately, both died."

Mali is home to the world's deadliest active U.N. mission. Haq said due to the confrontations on the ground with radical jihadists, the crash site would have to be secured before personnel could reach the scene.

Ahmad Makaila, a spokesman based in Mali with the U.N. mission known as MINUSMA, said earlier that two Germans were on board the helicopter and later confirmed that they were killed.

There was no immediate comment from the German military.

Germany currently has 875 troops serving in MINUSMA, while an additional 134 Germans are taking part in the European Union mission in Mali.

The U.N. mission has been working to stabilize Mali after a 2013 French-led intervention to oust radical jihadists from power in the country's major northern towns. Militants continue to launch regular attacks on peacekeepers as well as on Malian military targets.

U.N. peacekeeping chief Jean-Pierre Lacroix told the U.N. Security Council earlier this year that the security situation in Mali is alarming. He warned that extremist groups operating under the al-Qaida banner are carrying out more sophisticated attacks and that Islamic State militants were also slowly making inroads in the desert region.

"This convergence of threats is particularly alarming" because the government presence is often weak or non-existent in Mali, he said.

On Wednesday, Lacroix released a statement saying he was saddened by the news and "wishes to convey his profound sympathies to the families and loved ones of the victims and expresses his condolences to" the German government and MINUSMA personnel.

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Associated Press writer Edith M. Lederer at the United Nations contributed to this report.