http://www.star-telegram.com/2012/06/26/4059073/mild-earthquake-shakes-north-texas.html#0_undefined,0_

FORT WORTH -- Another earthquake shook North Texans on Monday night, this one near Alvarado in Johnson County.

A preliminary report from the U.S. Geological Survey says the magnitude-2.6 quake hit at 11:03 p.m. Monday about a mile south of the town south of Fort Worth.

It was the fifth quake in Texas since Saturday; no major damage has been reported in any of the quakes.

The first quake hit Saturday, two more were recorded Sunday and another one hit early Monday. The largest was a magnitude-3.6 temblor near Keene, also in Johnson County, on Sunday.

"The smaller ones are probably going to be aftershocks from the 3.6," said geophysicist Jessica Turner with the U.S. Geological Survey in Golden, Colo. "The aftershocks could come a few hours after the 3.6 or it could be days."

Turner said Tuesday that it's too early to say what's causing the Texas quakes.