The quake struck about 20 km (12.3 miles), north-west of the port of Port-de-Paix, the US Geological Survey said.
The Haitian Civil Protection Agency said early on Sunday that at least 135 people were being treated for injuries.
A local government representative said 152 people were injured in Port-de-Paix, and the most seriously hurt were taken by air ambulance to the capital Port-au-Prince for treatment.
This is Haiti's biggest quake since the 7.3 magnitude natural disaster struck near the capital, Port-au-Prince, in 2010 that killed over 230,000 of people and cost the already impoverished nation US$7.8 billion to $8.5 billion in damage.
Haiti, the poorest country in the Western Hemisphere, is still recovering from the catastrophic 2010 quake that killed at least 220,000 people and destroyed much of the capital city.More news: SCOTUS or bust: Kavanaugh forced to withdraw from teaching gig at Harvard
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Other deaths occurred in Gros Morne, a community in the Artibonite region, according to Eddy Jackson Alexis, the secretary of state for communications.
Le Nouvelliste newspaper said one person died when an auditorium collapsed in Gros Morne, and that detainees were released from a police holding cell that was damaged. The full extent of the damage was not clear though in parts of Port-de-Paix residents tried to go about their business normally on Sunday.
The Cuban ambassador to Haiti, Luis Castillo, confirmed to Prensa Latina that the embassy went undamaged. Another 30 were injured in Gros-Morne. Residents using saws or their bare hands scrambled to recover metal support rods from the debris for resale, before being chased away by authorities. At least 10 people have been killed by an quake, while over 135 people were injured as per the latest updates. Overall, around five million people were displaced by the quake when it struck the poorest country in the western hemisphere.
Longer-term reconstruction has been hampered by lingering political chaos in the nation of almost 11 million people, and by a deadly cholera epidemic introduced by infected Nepalese UN peacekeepers sent in after the quake.