Three short but sharp aftershocks from the Jan. 17 Northridge earthquake rattled homes in Simi Valley and the San Fernando Valley late Sunday and early Monday, but officials said no injuries or damage were reported.
The first aftershock, a magnitude 3.6, hit at 11:49 p.m. Sunday, according to seismologist Jim Mori at Caltech in Pasadena. It was followed by a 3.7 jolt a minute later.
Mori said both quakes were centered 3 miles southeast of Simi Valley.
The third aftershock, a magnitude 2.6, was centered two miles southeast of Simi Valley and hit Monday morning at 8:57 a.m., Caltech officials said.
Simi Valley Assistant City Manager Mike Sedell said the city received no damage reports after the trio of aftershocks.
"It's become almost routine," Sedell said. "People say, 'Did you feel it?' but that's about it."
No damage was reported in the San Fernando Valley, officials said.
At the Federal Emergency Management Agency office in Simi Valley, spokeswoman Pamela Korneisel said she had heard of no damage, but that residents tend to wait a while before asking for help.
"Usually we'll start to see people coming in later," Korneisel said.