A major earthquake struck western Haiti on Saturday, likely causing high casualties and widespread disaster, the U.S. Geological Survey said, and sending shock waves across the Caribbean, where people fled their homes for fear they might collapse.

The 7.2-magnitude earthquake quake struck 8 km (5 miles) from the town of Petit Trou de Nippes, about 150 km west of the capital Port-au-Prince, at a depth of 10 km, the USGS said.

That made the earthquake potentially bigger and shallower than the magnitude 7 earthquake that struck Haiti 11 years ago, killing tens if not hundreds of thousands of people, flattening buildings and leaving many homeless.

The U.S. Tsunami Warning System issued a tsunami warning after the quake, lifting it shortly thereafter, although Haitian media outlets reported some people along the coast had already fled to the mountains.

Haiti's Civil Protection service said on Twitter there were initial reports of likely casualties from its teams.

Images posted on social media - which Reuters was not immediately able to verify - showed homes and part of a church in the nearby town of Jeremie reduced to rubble.

"In my neighborhood, I heard people screaming. They were flying outside," said Port-au-Prince resident Sephora Pierre Louis, adding she was still in a state of shock. "At least they know to go outside. In 2010, they didn’t know what to do. People are still outside in the street."

The earthquake comes as Haiti is already mired in intertwined political, humanitarian and security crises.

The government is in turmoil, a month after the assassination of President Jovenel Moise, while swaths of the country are facing growing hunger and healthcare services are overwhelmed by COVID-19. Access to the southern region, where the quake struck, has been restricted by gang control of key areas.

"This country just never finds a break! Each year of mismanagement did not hurt but the cumulative effects made us vulnerable to everything," said Haitian entrepreneur Marc Alain Boucicault on Twitter.

"Its going to take years to fix things and we have not even started!"

The quake was felt as far as Cuba and Jamaica although there were no reports of material damage, deaths or injuries there.

"Everyone is really afraid. It's been years since such a big earthquake," said Daniel Ross, a resident in the eastern Cuban city of Guantanamo.

He said his home stood firm but the furniture shook.

"I feel it, man. It wake me up. My roof kind of make some noise," said Danny Bailey, 49, in Kingston.

The European-Mediterranean Seismological Centre (EMSC) also reported a quake in the region, saying it was magnitude 7.6, while Cuba's seismological centre said it registered a magnitude of 7.4.