New Delhi, April 14 -- Authorities in Haiti have arrested seven suspects, including five police officers, after a fatal stampede killed at least 25 people at a historic mountaintop fortress over the weekend, police said Monday.

Among the arrested are two employees of Haiti's Institute for the Preservation of National Heritage, which oversees La Citadelle, an imposing fortress in the northern town of Milot built in the early 1800s where Saturday's stampede occurred.

Dozens of people were injured, with 30 reported to still be in hospital on Sunday. It's not clear what caused the stampede. A police investigation is ongoing.

It wasn't immediately clear if the police officers or institute employees have been formally charged.

Milot Mayor W...