The US Geological Survey reported a magnitude 6.4 earthquake off the north coast of Puerto Rico just after midnight Monday morning.
Puerto Rico's emergency management agency did not issue a tsunami warning, and no injuries were reported, but some buildings and infrastructure sustained minor damage.
Residents of the capital city San Juan, about 61 miles away from the epicenter, felt buildings sway and saw furniture move across rooms.
The epicenter was beneath the Caribbean Sea, about 35 miles north of the coastal town of Hatillo, at a depth of 17 miles.
Some local reports said the shaking was prolonged, lasting about half a minute or more.
"I was in my bed and suddenly everything started to shake. The shaking lasted for more than 30 seconds," local resident Manuel Rivera told CBS news.
EarthquakeReport.com, an independent earthquake reporting site, received dozens of posts from people who felt the quake.
One commenter, posting from the east coast municipality of Humacao, wrote:
"I was shaking side to side in my chair, the glasses in cupboard where rattling, I put my hands on the walls and felt the shaking worsen, my Christmas tree was shaking/swaying back and forth an inch, chandelier swaying an inch. This lasted a long time, after a while I started counting and counted to 37, so it must have been for more than a minute. An hour before the quake my dog was whining and crying and scared, after the quake she is now quiet, very strange."
The Puerto Rican news site Noticel.com reported that the quake could be felt across the entire island and that the tremor was one the strongest to have shaken the island in recent history.
In recent years, Puerto Rico has experienced a number of strong earthquakes, including a 5.4-magnitude one that shook the US territory in 2011, and another of the same magnitude that hit in 2010, according to The Associated Press.