Another 13 people were injured in the crash in Gonaives, a city of some 300,000 people located about 150 kilometers (90 miles) northwest of the capital Port-au-Prince.
“First, the bus plowed into two pedestrians, killing one of them, and injuring the other,” Marie-Alta Jean Baptiste, head of Haiti’s civil protection office, told AFP.
The driver of the Blue Sky bus then rammed into three groups of street musicians as he tried to speed away, leaving a scene of ghastly carnage.
The number of injured was initially 17, but four victims later died at the hospital, the national police in Gonaives said.
Police were forced to control an angry crowd after the grisly incident. Drivers in Haiti who are involved in accidents rarely stop at the scene because they fear attack by local mobs seeking to extract vigilante justice.
“The people who were not victims of the accident tried to burn the bus with the passengers inside,” said Faustin Joseph, civic protection coordinator for the department of Artibonite, where Gonaives, the regional capital, is located.
The Blue Sky bus line, a private company offering long-distance routes, is an upscale option for travel in Haiti with modern, air-conditioned coaches.
Most Haitians generally travel on former American school buses which ply the roads, making frequent stops.
Authorities initially said they had detained the bus driver, but he had actually fled the scene, Gonaives traffic chief Jeudy Lisate told AFP. Police were still trying to identify him.
It’s not known what caused the crash, which occurred on a straight stretch of a national road without any potholes.
On Sunday afternoon a heavily damaged car was seen in a ditch on the side of the road, but the accident scene had otherwise been cleaned up.
In a statement Haitian President Jovenel Moise “expressed his deep sadness following the terrible accident.”
“The head of state conveys, on behalf of the whole government, his sincere condolences to the families and those close to the victims,” the statement read.
Moise called for “an investigation as soon as possible to shed light on this tragedy.”