Another small earthquake shook the Irving area again Sunday night, less than 24 hours after two stronger quakes rattled the area.The latest earthquake, which measured 2.1, occurred about 10:41 p.m. Sunday near Las Colinas Country Club not far from Carl Road and just north of Texas 183. There were no reports of injuries or damage.On Saturday, a 3.4 quake occurred at 11:05 p.m. about two miles north of Irving, according to the U.S. Geological Survey. It was followed by a second earthquake with a 3.1 magnitude about seven miles west of Dallas.Aftershocks could continue for several days."If someone was inside a home and close to the epicenter, there could have been things falling off shelves," geophysicist Don Blakeman said by telephone Sunday from the national earthquake monitoring center in Golden, Colo.Generally, depending on soil, structures and how close a building is to an epicenter, serious damage could occur at magnitude 4.5 or higher, Blakeman said. Injuries might be reported after a 5.0 quake.The preliminary magnitudes of the earthquakes could be revised after more data is obtained, officials said."We felt a rolling quake in Grapevine," Ray Wall of Grapevine said by e-mail to the Star-Telegram. Wall reported feeling the quake at about 11:15 p.m. Saturday. "This was followed five minutes later with a boom sound and feel."North Texas has been rattled by a number of minor quakes since 2008. Johnson County has had several rounds of small quakes, including this summer.Staff writer Bill Hanna contributed to this report.