A magnitude 5.1 earthquake hit Puerto Rico on Friday, rattling residents but causing no immediate reports of damage.

The U.S. Geological Survey said the quake, which occurred at 7:43 p.m. (6:43 p.m. ET), stuck about 15 miles (25 kilometers) south of San Juan. It was some 64 miles deep, the USGS said.

There were no immediate reports of damage or injuries.

A Federal Aviation Administration official said the international airport in San Juan was open and operating normally.

"It lasted about 30 seconds and felt hard. Some guests did get a little scared," said Venus Nevarez, an employee at the El San Juan Hotel and Casino. She said nothing broke and that all the guests were fine.