A Dutch military helicopter crashed in the Caribbean Sea near the island of Aruba, killing two of the four people on board, the Dutch defence ministry said on Monday.
Rob Bauer, the Dutch armed forces chief, said it was not clear what caused the helicopter to crash some 12.5 kilometres (7.77 miles) off the coast of the Dutch island at the end of a coast patrol surveillance flight on Sunday.
The helicopter's 34-year-old pilot Christine Martens and 33-year old tactical coordinator Erwin Warnies were killed. The other two crew members were not seriously injured, Bauer said.
Pending an investigation into the crash, all Dutch NH90 helicopters will be grounded until further notice.
There was no immediate comment from NHIndustries, the helicopter's manufacturer based in Aix en Provence, France.
Prime Minister Mark Rutte said he was shocked by the crash and offered his condolences to the victims' families.
North Korean leader Kim Jong Un told Russia's top diplomat his country was ready to "unconditionally support" Moscow's every effort to resolve the conflict in Ukraine, state media reported on Sunday, as the two countries held high-level strategic talks.
A preliminary report depicted confusion in the cockpit shortly before an Air India jetliner crashed, killing 260 people last month, after the plane's engine fuel cutoff switches almost simultaneously flipped, starving the engines of fuel.
US President Donald Trump defended the state and federal response to deadly flash flooding in Texas on Friday as he visited the stricken Hill Country region, where at least 120 people, including dozens of children, perished a week ago.
Russia pounded Ukraine with hundreds of drones and dozens of missiles on Saturday, in the fourth major attack this month, targeting western cities and killing at least two people in Chernivtsi on the border with Romania.