PORT-AU-PRINCE—Haitian President Jovenel Moise was shot dead by unidentified attackers in his private residence overnight in a “barbaric act,” the government said on Wednesday, stirring fears of escalating turmoil in the impoverished Caribbean nation. The assassination drew condemnation from Washington. The disorder has turned many districts of the capital into no-go zones. Interim Prime Minister Claude Joseph said in televised remarks after chairing a cabinet meeting that the government had declared a state of emergency amid confusion over who would take over the reins of the country. “My compatriots, remain calm because the situation is under control,” he said. The 53-year-old president’s wife, Martine Moise, was also shot in the attack at around 1 a.m. local time at the couple’s home in the hills above Port-au-Prince, Joseph said in a statement. She was receiving medical treatment. “A group of unidentified individuals, some of them speaking Spanish, attacked the private residence …