A pair of significant earthquakes struck North Texas yesterday, and they were joined by a cluster of smaller ones that rattled the Dallas area.

A total of eight earthquakes were reported in the region as locals reported feeling buildings shaking, according to the Dallas Morning News.

The first quake struck at about 3 p.m. about three miles beneath the Earth near the former home of the Dallas Cowboys, Texas Stadium, in Irving. The quake registered 3.5 on the Richter scale.

It was followed by another one measuring 3.6 at 7 p.m., also near the site of the old stadium, and then a pair of quakes measuring 2.9 and 2.7 struck at around 8 p.m. Two more weak earthquakes were felt at around 10 p.m., and a seventh hit the area at around 11 p.m.

Officials added one more earthquake at 7:37 a.m.

A total of 20 quakes have hit the Irving area since October, most of them centered around the stadium site. These most recent quakes, however, have been the strongest felt so far, beating out a 3.3 quake that hit the area in November.

Officials said there hasn’t been any injuries or damage reported, although there were a few calls to 911 over concerns about the shaking. Some water mains ruptured on Tuesday, but city officials weren’t sure if that had anything to do with the earthquakes.

Seismologists say they aren’t sure why the quakes are happening. More than a hundred have struck the region since 2008, despite it not being a hot spot for seismic activity.

He said it likely had to do with old faults that have stored stress, as potential human factors such as the disposal of wastewater and the oil and gas activity in the region didn’t appear to be causing the quakes.