Thousands of Haitians have their fled homes in Port-au-Prince amid soaring gang violence that has killed more than 2,400 people so far this year.
The UN said that 5,000 fled the Carrefour-Feuilles district this week after gang members took control.
Local aid groups meanwhile have stopped vital services as government attempts to quell the violence fell flat.
The UN Security Council is soon due to decide whether to send a multinational force to help restore order.
In Carrefour-Feuilles and surrounding areas where there has been months of gang warfare, a stream of residents were seen carrying suitcases or leaving with belongings strapped to their cars.
Video recorded by Reuters news agency showed women weeping beside the body of a man who gang members had killed.
Reuters said that many of those who managed to escape had gathered at a local military base demanding help against the gangs.
Decades of instability, disasters and economic woes have left Haiti one of the poorest and most-violent countries in the world.
Gang violence has soared since the assassination of President Jovenel Moïse in 2021, which led to much of the country’s territory falling out of government control.
Turf wars have since driven a surge in refugees, severe food shortages, murders, kidnappings and sexual violence.
UN rights office spokeswoman Ravina Shamdasani said on Friday that at least 2,439 Haitians had been killed, 902 injured and 951 kidnapped this year.
“Reports from Haiti this week have underscored the extreme brutality of the violence being inflicted on the population,” she said.
She added that vigilante groups set up to counter the gangs had led to 350 people being lynched since April. Of those, 310 were alleged gang members and one was a police officer.
According to provisional figures released by one local rights group, 30 people were killed and more than a dozen others wounded in attacks in the capital on Thursday.
The US embassy, which has already been evacuated of non-essential staff, closed down on Thursday due to sustained gunfire in the area.
Haiti’s government said it would deploy “all its forces” to restore order to Carrefour-Feuilles. However, its poorly equipped police have struggled against heavily armed gangs.
The International Red Cross said that “in a matter of days, violence escalated dramatically”, particularly in areas where it worked with local groups.
Roadblocks installed by warring gangs were stopping residents from getting help, it added.
Ann Lee, co-founder of US-based crisis response group CORE, which is still operating in the capital, said that many international groups had left due to increasing intimidation and violence against staff.
“We have a staff member who lost her daughter because she was having a seizure and couldn’t get to the hospital,” she said. “We have an employee whose brother was beheaded.”
Ms Lee said there was not a single member of CORE’s 100-strong Haiti team who did not know a victim of the violence.
UN Secretary-General Antonio Guterres told the Security Council in a report on Tuesday that a “robust use of force” by a multinational deployment was needed to restore order and disarm the gangs.
Kenya has expressed willingness to lead such a force. The council is due to consider the matter in the coming weeks.