A military helicopter crashed into Qatari waters during a training flight on Sunday, killing everyone aboard, Qatari authorities say.
All seven victims were recovered from the wreckage, officials added.
The Qatari interior ministry extended condolences to the families of the deceased.
Those on board included four Qatari service members, one Turkish soldier and two technicians employed by Turkish defence firm Aselsan.
Turkey’s defence ministry said the aircraft was participating in activities linked to the Qatar-Turkey Joint Forces Command.
Qatari authorities reported the aircraft suffered a technical fault and have launched an inquiry to establish the exact cause.
Turkish officials said they would await the findings of that investigation.
Turkey maintains a military presence in Qatar under a 2014 defence agreement between the two countries, and the base plays a central role in bilateral cooperation.
The crash comes amid heightened regional tensions, with ongoing exchanges of strikes and retaliatory attacks involving Iran and actors across the Gulf.
Investigators have not yet released a timeline for their report.
