Heavy gunfire and traffic disruptions were seen on Friday in some areas of Haiti's capital, the local US embassy said on Friday, a day after other violent events left four police officers dead.
Violence has sparked during Primer Minister Ariel Henry's visit to Kenya this week.
Earlier on Friday, the two countries signed a deal to secure a plan to send 1,000 police officers to lead a UN-approved mission aimed at tackling gang violence in the Caribbean nation.
Kenya announced plans in July last year to lead the mission to Haiti, where gangs control most of the capital and nearly 5,000 people were killed in the violence last year.
But Kenya's High Court ruled the deployment, initially expected by January, unconstitutional in the absence of a "reciprocal arrangement" with the host government.
That has effectively placed the entire mission on hold, even as the United States and Canada have pledged hundreds of millions of dollars to it, and some countries have committed armed personnel.
Wave of violence
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 Haiti's Prime Minister Ariel Henry arrived in Kenya for talks on the deployment of a multinational security mission in the country backed by the United Nations.
By midday, most institutions and businesses in the city 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.