An earthquake rattled parts of Northern California Wednesday, with aftershocks felt across the Bay Area.The US Geological Survey said the quake, with a preliminary magnitude of 5.6, struck at 8:10 a.m. local time approximately 140 miles (225 kilometres) northeast of San Francisco. Its epicentre was located inland, about 50 miles (80 kilometres) east of the fishing town of Fort Bragg.A smaller 2.5 magnitude tremor was recorded near the epicentre just minutes later, and USGS said some damage was possible but that the impact should be relatively localized. Shaking was widely felt across the region. One resident told local TV outlet KRON that the earthquake lasted about seven seconds, and a second person said it was strong enough to knock things off shelves.Fawnell Dale, a dispatch supervisor for the Mendocino County Sheriff’s Office, characterized the shaking as mild and said that no reports of damage or injuries had been received.The 5.6-magnitude earthquake struck in inland Mendocino County, just southeast of Willits (USGS)At Mendocino Coast Pharmacy, staff preparing to open for the day received earthquake alerts on their mobile phones. An employee, identified only as Angie, recounted: "We looked at our phones, then we looked at each other, and that’s when we felt it." She described a brief, "rolling shake" lasting a few seconds, adding: "It wasn’t that big, but it was a little scary." Andrea Medina, from Cafe One in Fort Bragg, also felt the ground move. "Things were shaking," she said, adding, "But it’s done, not too strong."Approximately 60,000-70,000 people reported experiencing moderate to very strong shaking, and around 10 million people felt weak to light shaking.