(CNN)Four suspects connected to the assassination of Haiti's President Jovenel Moise were killed by police on Wednesday, and another two have been detained, Haiti's ambassador to the United States said.
Speaking to CNN en Español on Wednesday night, Ambassador Bocchit Edmond said the suspects were foreigners and Haitian National Police were in the process of determining their nationalities.
"We are trying to move forward and see how we can identify more of those who participated in this horrible act," he said.
It comes after President Moise was killed during an attack on his private residence early on Wednesday. The attackers stormed Moise's home at around 1 a.m. and fatally wounded the head of state.
Haiti's first lady, Martine Moise, was shot in the attack and was evacuated to a hospital in Miami for treatment, according to Edmond, who said her condition is stable but critical. Images showed the first lady on a stretcher arriving at Jackson Health System's Ryder Trauma Center in Miami.
Moise's death takes place against a background of extreme violence in Haitian capital Port-au-Prince that has claimed the lives of many citizens and escalated notably in June. Acting Prime Minister Claude Joseph, who declared a state of seige in the country, described the assassination as a "heinous, inhumane and barbaric act" and pleaded with citizens to remain calm.
Police have not publicly identified the suspected attackers and little is known about who carried out the assassination.
Ambassador Edmond said he believed the suspects received assistance from Haitian nationals due to vehicles they used to get to the presidential residence where the President was killed. He had earlier referred to them as "mercenaries" and "well-trained killers."
Video from the scene showed them speaking Spanish and they presented themselves as Drug and Enforcement Administration (DEA) Agents, he said.
"I believe they are fake DEA agents," he told reporters Wednesday.
"We don't know how they came in," Edmond said, adding that they did not know if the attackers were still in the country. He said if they have left, it would be via a land border with the Dominican Republic because Haiti would have detected a plane leaving and the airport has been closed since the attack. He said the airport would reopen "once we have this situation under control."
The state of siege is the middle of three levels of emergency under Haitian law, alongside the lower "state of emergency" and the highest level referred to as the "state of war."
Under the state of siege regime, national borders are closed and martial law temporarily is imposed, with Haiti's military and national police empowered to enforce the law.
Moise, 53, was a former banana exporter and divisive figure in Haitian politics. He spent most of the past year waging a political war with the opposition over the terms of his presidency.
For now, it isn't immediately clear who will replace him. Judge Jean Wilner Morin, President of the National Association of Haitian Judges, told CNN the line of presidential succession in the country is now murky.
Haiti's President of the Supreme Court would normally be next in line, but he recently died of Covid-19. For the acting Prime Minister Joseph to formally replace the President, he would have to be approved by Haiti's parliament, said Morin. But without recent elections, the parliament is effectively defunct.
Throughout his presidency, Moise had repeatedly failed to hold elections at local and national levels, leaving much of the country's governing infrastructure empty. A constitutional referendum is set to be held in September, alongside the presidential and legislative elections. Municipal and local elections have been scheduled for January 16, 2022, the official electoral calendar also showed.
Many in the country had disputed Moise's right to continue serving in the presidency this year.
Moise's private residence is in Petion-Ville, in Haiti's capital Port-au-Prince.
While the US, United Nations and Organization of American States supported his claim to a fifth year in office, critics say he should have stepped down on February 7, citing a constitutional provision that starts the clock once a president is elected, rather than when he takes office.
Moise, however, claimed his five-year term should end in 2022 because he wasn't sworn in until February 2017. His inauguration was delayed over allegations of voter fraud during the 2015 election, which led to a presidential runoff that was postponed twice over what authorities called threats and "security concerns."
Haiti's capital has been reeling from violence for weeks, with rival groups battling one another or the police for control of the streets, displacing tens of thousands of people and worsening the country's humanitarian crisis.
Ex-police officer Jimmy Cherizier last week vowed before local media to carry out a "revolution" in the city.
Meanwhile, the coronavirus pandemic has been worsening in Haiti. The country is one of only a handful across the world that have not yet started vaccinating against the virus.
Last month, the Pan American Health Organization (PAHO) warned that the response in the country must be scaled up dramatically to cope with sharply escalating cases, hospitalizations and deaths. Haiti has reported more than 19,000 Covid-19 cases and 467 deaths, according to the Johns Hopkins University tally.
At the same time, the impoverished Caribbean nation is facing a dire economic situation. Its economy had been contracting even before the pandemic and shrunk further 3.8% in 2020, with about 60% of the population now living in poverty, according to the World Bank.
UNICEF, the United Nations' children's agency, said in May that severe acute childhood malnutrition is expected to more than double in Haiti this year as it deals with rising violence, Covid-19 and a lack of access to essential services.
CNN's Ivana Kottasová, Caitlin Hu, Sharon Braithwaite, Claudia Rebaza, Jennifer Hansler, Emmet Lyons, Melissa Bell and Stephanie Halasz contributed reporting.