More than 2,400 people have been killed in Haiti since the start of 2023 amid rampant gang violence, including hundreds killed in lynchings by vigilante mobs, the UN said Friday.

The toll comes as clashes in Haiti's capital of Port-au-Prince this week left 30 residents dead and more than a dozen wounded.

"Between January 1 and August 15 of this year, at least 2,439 people have been killed and a further 902 injured," UN rights office spokeswoman Ravina Shamdasani told reporters in Geneva.

In addition, she said, "951 people have been kidnapped" during the same period.

And as anger grows, she warned that a rise in popular justice movements and self-defence groups was fuelling the fire.

"Since April 24 up to mid-August, more than 350 people have been lynched by local people and vigilante groups," she said, adding that of those, 310 were alleged gang members and one was a police officer.

The remainder were members of the public.

Houses in Port-au-Prince's Carrefour-Feuilles neighbourhood were set on fire in the attacks and two police officers also died, according to a provisional toll provided to AFP by the National Human Rights Defense Network.

The neighbourhood is a strategic area for the gangs, which control about 80 percent of Haiti's capital. More than 5,000 people have fled their homes, authorities said.

Violent crimes include kidnappings for ransom, carjackings, rapes and armed thefts.

"Reports from Haiti this week have underscored the extreme brutality of the violence being inflicted on the population and the impact that it is having on their human rights," Shamdasani said.

In the face of the violence, UN rights chief Volker Turk called for urgent action to be taken on an appeal for a non-UN multinational force to be sent in "to support the Haitian police in addressing the grave security situation and restoring the rule of law".

"The human rights of the Haitian people must be protected and their suffering alleviated," Turk said.

At the end of July, Kenya announced it was ready to lead a multinational force and deploy 1,000 police "to help train and help the Haitian police restore normality in the country".

Haiti has been mired for years in intertwining economic, security and political crises.

The assassination of President Jovenel Moise in 2021 has dramatically worsened the situation, with gangs taking an increasingly strong hold.

The head of the Haitian National Human Rights Defense Network said that the population had been "left to fend for itself".

"The national police is dysfunctional and is facing leadership problems," said Pierre Esperance, criticizing the "highest level connivance" with the crime gangs.

"The Haitian police cannot solve the problem of insecurity because it is part of insecurity," he said, noting that the crisis cannot be tackled "without tackling the problems of governance, the absence of the rule of law, impunity and political instability".