Special police units were deployed throughout Port-au-Prince and national police trade union said four officers had been killed, including a chief inspector.
A wave of panic swept through downtown Port-au-Prince on Thursday as violence and heavy gunfire broke out, in what a gang leader said was a demonstration against authorities.
The armed clashes involving gangs, police and vigilantes took place on the same day that Haiti's Prime Minister Ariel Henry arrived in Kenya for talks on the deployment of a multinational security mission to his nation which was backed by the United Nations.
By midday, most institutions and businesses in Port-au-Prince had closed and thousands of people were trying to flee the downtown area on foot or public transport, witnesses said.
Special police units were deployed throughout the city and national police trade union Synapoha said four officers had been killed, including a chief inspector.
Haitian airline Sunrise Airways halted flights as violence flared, a company spokesperson said, adding shootouts near the capital's airport had put people in danger.
"We have chosen to take our destiny in our own hands. The battle we are waging will not only topple the Ariel (Henry) government. It is a battle that will change the whole system," said former cop and gang leader Jimmy Cherizier, also known as Barbecue, in a video shared on social media.
Henry, who came to power after the assassination of the country's last president in 2021, had pledged to step down by early February, but later said security must first be re-established to ensure free and fair elections.
Violent gangs have since expanded their territory and are now estimated to control most of the capital. The UN estimates the conflict killed close to 5,000 people last year and has driven some 300,000 from their homes, while the fighting has blocked off access to food and medical services.
A UN spokesperson on Thursday said five countries had formally notified the global human rights body of their intent to contribute personnel to the international force, which Henry had urgently requested in 2022.
No numbers have been given for the potential force and a deployment date has yet to be announced. Henry, who has said security must be reestablished to hold fair elections, told regional leaders this week he would hold a vote by August 2025.