New Delhi, April 12 -- At least 30 people were killed on Saturday in a stampede in the northern countryside of Haiti, authorities said, warning that the death toll could rise.

Jean Henri Petit, head of Civil Protection for Haiti's Nord Department, said the stampede occurred at the Laferriere Citadel, an early-19th-century fortress built shortly after Haiti's independence from France.

One of Haiti's most popular tourist attractions, the fortress was packed with students and visitors on Saturday who had come to participate in the annual celebration of the UNESCO World Heritage site, Petit added.

The Prime Minister Alix Didier Fils-Aime said in a statement that he "extends his sincere condolences to the bereaved families and assures them ...