A major earthquake struck south of Cuba on Tuesday, sending shockwaves as far as Miami and sparking panic in the Cayman Islands where it ripped open sinkholes, but did not do serious damage to people or property, initial reports said.

The magnitude-7.7 quake hit in the sea between Jamaica, the Cayman Islands and Cuba, at a depth of 10 kilometers. Several aftershocks, including one of 6.1 magnitude much nearer to the Cayman Islands, followed the principal quake.

Cindi Welcome, 27, a trainee travel agent in Cayman capital George Town, said she first thought her blood pressure was playing up when the tremors struck. Then she screamed.

"The building was shaking like paper," she said. "The panic was real. This was the worst we have ever felt."

Residents reported drains blowing open and sinkholes appearing, one of which swallowed half a car, said Jewel Hydes, a 44-year-old risk manager on the islands.

"It was really, really horrific. Everyone on the island is still in shock," Hydes said. "We kept seeing tons of people praying, running out of buildings, 'cause they were swaying."

In Miami, Florida, several downtown buildings were evacuated as office workers streamed outdoors to safety.

Miami personal injury attorney Eli Stiers was in his 29th floor office when he suddenly started feeling queasy.

"I was like: 'Did I have some bad sushi?'" he said. Then he noticed his office door swinging back and forth. "We were like, did a plane hit the building? A sinkhole open up? Then it hit us that it was an earthquake. You don't expect that in Miami."

The Miami-Dade Fire-Rescue department responded to multiple calls about high-rise buildings swaying. The department said it had no reports of injuries or structural damage.