Haitian president Jovenel Moïse was shot dead by unidentified attackers in his home overnight in a “barbaric act”, the government said on Wednesday, stirring fears of escalating turmoil in the impoverished Caribbean nation.

The assassination coincided with a wave of gang violence in Port-au-Prince as armed groups have battled with police and one another for control of the streets in recent months, turning many districts of the capital into no-go zones...