WASHINGTON — A series of individual and organizational failures, including a lack of training and situational awareness, led to a deadly ambush in Niger last year that killed four U.S. soldiers, a partial Pentagon report released on Thursday said.

The October ambush, which was carried out by a local Islamic State affiliate, has thrown a spotlight on the U.S. counterterrorism mission in the West African country and the report will raise more questions about U.S military operations on the continent.

President Donald Trump’s handling of condolence messages to the families of the dead U.S. soldiers has been criticized by lawmakers in Washington and raised the profile of the deadly incident.

"The investigation identifies individual, organizational and institutional failures and deficiencies that contributed to the tragic events of 4 October 2017 ... no single failure or deficiency was the sole reason for the events," an eight-page summary of the report says. A redacted version of the complete report may not be publicly released for months.

Even before the U.S. Special Operations Forces Team arrived in Niger, high personnel turnover had prevented the team from carrying out important pre-deployment training as a team, the report found.

Only half of the team members had trained together when they arrived in Niger in the fall of 2017.

On Oct. 3, the special forces team, along with partner Nigerien forces, set out on a mission to target a key Islamic State militant near the village of Tiloa, Niger. The team had not trained for this mission and did not notify higher-level commanders that it would be undertaking it.

While the team mischaracterized this mission, the report did not find a direct link between that and the ambush that killed the four U.S. soldiers.

The top U.S. general said last year that the team was on a reconnaissance mission.

On the way back to its base, after carrying out a separate mission to gather intelligence, the team stopped at the village of Tongo Tongo to resupply. It was then that the U.S. soldiers, along with their Nigerien partners, were ambushed by 50 militants.

The report and a 10-minute video shown to reporters details the gun battle and how at one point U.S. Army Sergeant La David Johnson sought to run away from the militants. He was ultimately killed about 3,300 feet away from his vehicle.

The report leaves key questions unanswered, such as why the team took nearly an hour to call for support after it had come under fire and who will be held accountable.

As a result of the incident, the U.S. military has ordered a review of training for special forces soldiers working with foreign partners and policies on pre-deployment training, and U.S. Africa Command is seeking to create clear guidance on the planning and approval of military operations.

In Niger, Washington has deployed around 800 soldiers, runs a drone base in the capital, Niamey, and is building a second in Agadez at a cost of around $100 million.