FERNDALE, Calif. (AP) — A strong earthquake shook parts of Northern California early Tuesday, jolting residents awake, cutting off power to thousands, and causing some damage to buildings and roads, officials said. Two injuries were reported.

The magnitude 6.4 earthquake occurred at 2:34 a.m. near Ferndale, a small community about 210 miles (345 kilometers) northwest of San Francisco and close to the Pacific coast. The epicenter was just offshore at a depth of about 10 miles (16 kilometers). Numerous aftershocks followed.

The Humboldt County Office of Emergency Services initially tweeted that there were reports of “widespread damages to roads and homes,” but authorities subsequently indicated that damage was less than what might be expected from the size of the temblor.

The region is part of California’s lightly populated far north coast, home to redwood forests, mountains, a port and a state university. Long before the state legalized marijuana, Humboldt was part of the three-county Emerald Triangle where clandestine cannabis production was legendary.

Two injuries were reported but both people were expected to recover, county sheriff’s information specialist Samantha Karges said in an email to The Associated Press.

No fatalities were immediately reported, said Brian Ferguson, a spokesperson for the California Governor’s Office of Emergency Services.

There is “some damage” to buildings and infrastructure, and two hospitals in the area lost power and were running on generators, but the scale of the damage appeared to be “minimal” compared to the strength of the quake, he said.

Authorities closed an important bridge in Ferndale that was showing damage. The state highway department tweeted a photo showing crumpled pavement.

Some gas leaks were also reported and more than 70,000 customers lost power in the area, according to poweroutage.us.

Humboldt County has about 136,000 residents and is in a part of the state that has a long history of large earthquakes, including a magnitude 7.0 in 1980 and a 6.8 in 2014, according to the California Earthquake Authority.

The city of Eureka, population 26,000, said on its website that its communications center was receiving a high volume of calls but “no significant damage” was immediately reported.

Eureka resident Dan Dixon, 40, said he and his wife were sleeping when it jolted them awake and shook everything, throwing pictures in their home to the ground. Their infant daughter, he said, slept through it.

“It was probably the most violent earthquake we have felt in the 15 years I have lived here,” he said. “It physically moved our bed.”

Caroline Titus, a resident of Ferndale, tweeted video in her darkened home of toppled furniture and smashed dishes.

“Our home is a 140-year-old Victorian. The north/south shaking is very evident in what fell,” she tweeted.

“That was a big one,” she said in another tweet.

The earthquake occurred in an area known as the Mendocino Triple Junction, where three tectonic plates meet.

“We’re in this moment of geologic time where the most exciting, dynamic area of California happens to be Humboldt County and the adjacent offshore area,” said Lori Dengler, professor emeritus of geology at Cal Poly Humboldt, who happened to be 200 miles (322 kilometers) away in Sacramento when the quake struck.

Dengler said it is typical for there to be uncertainty about damage after a large earthquake. But she noted that much of the area is rural and wood frame construction is common, which in the past has helped limit damage.

The quake triggered the West Coast’s warning system that detects the start of a quake and sends alerts to cellphones in the affected region that can give people notice to take safety precautions before strong shaking reaches them.

About 270,000 people received notifications early Tuesday, said Ferguson, the Cal OES spokesperson.

The earthquake came just days after a small magnitude 3.6 earthquake struck the San Francisco Bay Area, waking up thousands of people before 4 a.m. Saturday and causing minor damage.

That earthquake was centered in El Cerrito, about a 16-mile (25-kilometer) drive to downtown San Francisco.