Haiti's President Jovenel Moïse has been shoot down and his wife injured in an attack on their house in the nation's capital, Port-au-Prince.
Unknown gunmen stormed the property at 01:00 local time (05:00 GMT), interim PM Claude Joseph said.
He has called for calm and declared a state of emergency nationwide.
Mr Moïse had led Haiti, one of the poorest nations in the world, since 2017 but had faced national wide protests demanding his resignation.
The nation's new history has been blighted by coups, political instability and widespread gang violence.
UK Prime Minister Boris Johnson tweeted that he was "saddened at the death of Mr Moïse", calling it "an abhorrent act" and appealing for calm. US President Joe Biden offered condolences to the people of Haiti for the "horrific assassination".
First Lady Martine Moïse later supposedly arrived by plane in Fort Lauderdale, south Florida, for treatment. There is no official word on her condition.
