Prime Minister Ariel Henry, writing on Twitter, said medical teams were being dispatched to the site, and declared three days of mourning.
Mr. Henry later said he would be traveling to Cap-Haïtien with a number of government officials, doctors and emergency medical workers.
“I will take this opportunity to express my solidarity with the grieving families,” he added.
The two major hospitals in the area were both overwhelmed by dozens of people needing care, hospital officials said, and were asking for help from other hospitals and the public because they lack even the most basic supplies, such as sheets, to attend the wounded.
The injured included burn victims, officials said, and those who were trampled as people fled the scene.
The country’s services, long in a state of disrepair, have been battered as Haiti has been rocked by cascading tragedies.
Since July, when President Jovenel Moïse was assassinated, the Caribbean island nation has suffered a devastating earthquake and flash floods, disasters that left over 2,000 dead and many more injured and displaced.
The natural disasters have been compounded by poverty, hunger and increasing violence.
In recent months, a severe fuel shortage pushed the nation even deeper into collapse. Gangs, not the government, now control large areas of the country, and they have taken advantage of the need for fuel, hijacking gas trucks at will and blocking deliveries. Many truck drivers refused to work in October, in a nationwide strike that paralyzed the country.