An earthquake with a preliminary magnitude of 2.6 was detected in Baltimore County, Maryland Friday afternoon, the US Geological Survey said, but there were no reports of injuries or damage.

“We got a couple of calls, I think there were four, from people who said they felt or heard something unusual,” said Elise Armacost, a spokeswoman for the county fire department.

Firefighters have been sent to look for damage, she said. No damage was reported around 4:30 p.m.

There was apparently more excitement on the internet than in Woodlawn, Md., An unincorporated area of ​​Baltimore County near the center of the quake, about 10 miles outside of Baltimore.

One person said on Twitter that it “sounded more like an explosion” as the earthquake spread.

Paul Caruso, a geophysicist with the Geological Survey, said earthquakes in the Maryland area are rare but are not unknown. Friday’s earthquake occurred along a “tiny” fault line, which is why it wasn’t as strong, he said.

“It’s nothing like the San Andreas,” said Mr. Caruso, referring to the great fault line in California. “The largest earthquake that can occur on a fault is directly related to the size of the fault. That is why the San Andreas is able to cause earthquakes of such magnitude. “

There are tiny fault lines in the United States that have the potential to create tiny earthquakes, Caruso said.

It was unclear if there would be aftershocks from the Friday quake, but Caruso said any aftershocks would, by definition, be weaker than the original earthquake.

Alan DeLacruz, who works at the Las Vegas restaurant in Baltimore County, said he felt nothing. “No, nothing here,” said Mr. DeLacruz. “I’ve never felt one here before.”

The restaurant is near the earthquake epicenter, which was on Windsor Mill Road and Security Boulevard, Baltimore County’s emergency management services said.

The restaurant staff went about their day as usual, said Mr DeLacruz.

“I never knew we would have earthquakes here,” he added.