The government of Haiti declared a 72-hour state of emergency on Sunday after armed gangs stormed a major Port-au-Prince prison, leading to the killing of at least 12 people and the escape of around 4,000 inmates.
Gang leaders say they want to force the resignation of Prime Minister Ariel Henry, who is currently abroad.
The groups aiming to oust him control around 80% of Port-au-Prince.
Violent gang wars have killed thousands in the country since 2020.
A government statement said two prisons – one in the capital and the other in nearby Croix des Bouquets – were stormed over the weekend.
It said the acts of “disobedience” were a threat to national security and said it was instituting an immediate night-time curfew in response, which started at 20:00 local time (01:00 GMT on Monday).
Among those detained in Port-au-Prince were gang members charged in connection with the 2021 killing of President Jovenel Moïse.
The latest upsurge in violence began on Thursday when the prime minister travelled to Nairobi to discuss sending a Kenya-led multinational security force to Haiti.
Gang leader Jimmy Chérizier (nicknamed “Barbecue”) declared a co-ordinated attack to remove him.
“All of us, the armed groups in the provincial towns and the armed groups in the capital, are united,” said the former police officer, who is thought to be behind several massacres in Port-au-Prince.
Haiti’s police union had asked the military to help reinforce the capital’s main prison, but the compound was stormed late on Saturday.
Violence has been rife since President Moïse’s assassination in his home in 2021. He has not been replaced and elections have not been held since 2016.
Under a political deal, Henry was due to stand down by 7 February. But planned elections were not held and he remains in post.
Haiti has not had a single elected government official since the term of the last elected senators expired in January 2023.
In January, the UN said more than 8,400 people were victims of Haiti’s gang violence last year, including killings, injuries and kidnappings – more than double the numbers seen in 2022.
Anger at the shocking levels of violence, on top of the political vacuum, has led to several demonstrations against the government, with protesters demanding the resignation of the prime minister.