The earthquake struck 8 km (five miles) from the town of Petit Trou de Nippes, about 150 km (93 miles) west of the capital Port-au-Prince, at a depth of 10 km, said the US Geological Survey.
The United States Geological Survey has issued a red alert for earthquake deaths and said the disaster is “likely widespread.”
The US Tsunami Warning System has signaled that the threat of a tsunami in Haiti has now passed.
Residents of the capital Port-au-Prince felt the shock and many rushed into the streets in fear.
Haiti’s civil protection service said on Twitter that there were first reports of probable casualties from its teams.
The Caribbean country is still recovering from a magnitude 7 earthquake closer to the capital 11 years ago that killed tens of thousands of people and destroyed buildings, leaving many homeless.
“In my neighborhood, I heard people screaming. They were flying outside, ”said Sephora Pierre Louis, a resident of Port-au-Prince, adding that she was still in shock.
“At least they know how to get out. In 2010, they didn’t know what to do. People are still out in the streets. “
Naomi Verneus, a 34-year-old resident, said she was awakened by the earthquake and her bed was shaking.
“I woke up and didn’t have time to put on my shoes. We lived through the 2010 earthquake and all I could do was run. Later, I remembered that my two children and my mother were still inside.
“My neighbor came in and told them to get out. We ran down the street, ”Verneus said.
Tropical Storm Grace is expected to reach Haiti late Monday evening or early Tuesday morning.