A magnitude-5.6 earthquake struck in Oklahoma late Saturday, the U.S. Geological Survey said, toppling a chimney, damaging buildings, and sending a boulder the size of a sport-utility vehicle onto a rural road.

The quake was the strongest in Oklahoma history, topping a temblor of magnitude 5.5 in 1952, according to the USGS.

It was the second earthquake of significant magnitude recorded in the state within 24 hours: A quake of magnitude 4.7 shook it early Saturday. Both quakes were centered east of Oklahoma City in Lincoln County.

[In all, the USGS has reported 15 earthquakes in Oklahoma this weekend as of 4 a.m. CST, with their magnitudes ranging from 2.7 to 5.6. Their epicenters all have been close to Sparks, Prague, or Meeker.]

There were no reports of serious injuries or deaths.

J.L. Gilbert, owner of the Sparks Vineyard and Winery, about four miles from the epicenter of the strongest quake, said it lasted a good 30 seconds.

It was a pretty good jolt. We're not used to this. We're used to being sucked up into the wind, he said, referring to Oklahoma's reputation as a tornado alley.

One of Gilbert's employees went to the hospital after tripping and hitting his head on a doorway while scrambling to get out of his home, Gilbert said.

In Prague, close to where the earthquake was centered, City Manager Jim Greff said the stongest temblor caused a chimney to topple over and crash through the roof of a home.

Part of the ceiling grid in the Prague library collapsed during the quake, but the walls remained intact, Greff said.

The earthquake caused state Highway 62 to buckle in three places west of Prague and sent a boulder about the size of an SUV tumbling onto a rural road in southeastern Lincoln County, said Aaron Bennett, dispatch supervisor for the county's emergency-management division.

Four aftershocks from the first big quake were felt by 1 a.m. Sunday, Bennett said.

The quake was felt more than 300 miles away in Kansas City, where it rattled windows and shook houses for half a minute, a Reuters witness said.

The second big quake was a shallow 3.1 miles (5 km ) deep and was centered 4 miles east of Sparks, which is east of Oklahoma City.

Earthquakes of a 4.0 magnitude east of the Rocky Mountains can typically be felt from up to 60 miles away, according to the USGS. A 5.5 magnitude quake can be felt up to 300 miles from its epicenter.

(Editing by Greg McCune and Vicki Allen)