RENO, Nev. (AP) — A months-long swarm of earthquakes picked up again Sunday as a string of minor temblors rattled Reno, causing downtown high-rises to sway and knocking items off walls and shelves.

There were no immediate reports of injuries or major property damage after about 20 minor quakes reported on the western edge of Reno over 12 hours ending about noon.

Magnitude-3.9 and 3.6 quakes struck within a couple minutes of each other shortly before 11 a.m. and were preceded by 3.2 and 3.0 quakes early Sunday, said researchers at the seismological laboratory at the University of Nevada, Reno.

"I was thinking, 'Here we go with the big one,"' said Daryl DiBitonto, a Reno resident who felt the quake at home.