Seven people have been arrested in connection with a deadly stampede at a popular tourist destination in Haiti, the country's national police force says.

The incident took place on Saturday during an annual cultural festivity at the Laferrière Citadel, a Unesco World Heritage site in northern Haiti.

The authorities initially reported that 30 people had been killed but this number has been revised down to 25.

Those arrested include five local police officers and two employees of the country's National Heritage Preservation Institute (ISPAN), which oversees the preservation of Haiti's major landmarks. They are currently in custody pending further legal action, police said.

An investigation into what happened has been launched but Prime Minister Alix Didier Fils-Aimé said on Saturday that the stampede happened "during a tourist event attended by many young people" at the site, in the town of Milot.

He added that three days of national mourning for the victims would begin on Tuesday.

Milot Mayor Wesner Joseph told the Magik9 radio station on Monday that his administration was not aware of any activity planned at the citadel on Saturday, and that they had later found out that a local DJ had invited people there via TikTok.

Jean-Hérold Pérard, the site's engineer and a former ISPAN director, told the Haitian Times that one of the site's two entrances had been closed so that local security officials could collect visitors' fees.