IRVING, Texas (AP) — Experts say a minor earthquake has shaken parts of North Texas as residents farther south brace for Hurricane Harvey.

The U.S. Geological Survey reports the 3.1 magnitude quake happened Friday at 6:41 a.m. The quake was centered about 3 miles (5 kilometers) northeast of Irving, a Dallas suburb.

Irving police say there were no immediate reports of damage or injuries.

The Irving area recorded at least six earthquakes during a two-month period in late 2014, at a time when small quakes became more common in parts of North Texas. The Texas Railroad Commission, which governs the oil and gas industry, soon amended rules for disposal well operators amid concerns that high-pressure injections can trigger earthquakes.

The USGS says about three dozen similarly small earthquakes have hit the area since then.