Haiti's national police did not immediately respond to a request for more details, or whether there had been any police casualties.

The clash follows days of protests across the country ahead of the Feb. 7 date by which current unelected Prime Minister Ariel Henry had promised to step down by, and on which Haitian presidents are traditionally sworn into office.

Former coup leader Guy Philippe, who was repatriated to Haiti late last year after serving some six years in a U.S. prison, in recent weeks had been rallying supporters to a "revolution" against Henry's government.

Local media AyiboPost reported citing the head of BSAP saying that many of its members are former soldiers who fought with Philippe in the 2004 ouster of former President Jean-Bertrand Aristide.

Henry, who assumed power after the assassination of Haiti's last president in 2021, last week called on BSAP members to register with the country's environmental ministry in an apparent crackdown against the agency.

Henry is expected to give a national address later on Wednesday. In December 2022 he had signed a non-binding accord to step down by Feb. 7, 2024, but has since said security conditions must be re-established to hold free and fair elections.

The events come as police battle alliances of heavily-armed gangs estimated to control most of Haiti's capital, fueling a humanitarian crisis that has seen hundreds of thousands flee their homes to escape the violence.

(Reporting by Harold Isaac and Steven Aristil in Port-au-Prince; Writing by Sarah Morland and Kylie Madry; Editing by Leslie Adlerby)