ORLANDO, Fla. — A strong earthquake rocked the island of Puerto Rico late Monday.

• Strong earthquake strikes just off the coast of Puerto Rico
• Island's governor says in a tweet that there were no injuries
• Tropical Storm Karen is about to bring heavy rain, wind to island

The U.S. Geological Survey said a 6.3-magnitude temblor struck about 44 miles north of the U.S. territory just after 11 p.m. local time.

There were at least three aftershocks, including one that was magnitude 4.7, according to the agency.

Meanwhile, Tropical Storm Karen was just south of San Juan and was expected to bring significant rain and wind Tuesday.

There were no immediate reports of damage and no risk of tsunami, said Kiara Hernández, a spokeswoman for the island's Emergency Management Agency, which was already on alert ahead of the tropical storm. She said the National Guard had also already been activated.

Puerto Rico Gov. Wanda Vázquez Garced posted a tweet also saying there was no damage nor threat of a tsunami.

Information from the Associated Press was used in this report.