Officials say multiple aftershocks followed the 4.8-magnitude earthquake that hit the northeast early Friday.

Tremors were felt from Washington, DC, to New York City to Maine, and the U.S. Geological Survey (USGS) said it was the strongest earthquake to hit New Jersey in more than 200 years, CNN reported Saturday.

The outlet continued:

There have been at least 18 aftershocks since the quake, including a 4.0 magnitude recorded southwest of Gladstone, 20 minutes from the epicenter, at 5:59 p.m., the USGS said Friday night. There is a 74% chance of magnitude 3 and above aftershocks happening within the next week, and just 1% chance of aftershocks magnitude 5 and stronger, the USGS estimates in its aftershock forecast.

USGS said the initial earthquake occurred at 10:23 a.m. The New York City Fire Department said the department received reports of shaking buildings about 10:30 a.m.

When the earthquake hit, officials began working to determine if there was any damage incurred, according to Breitbart News. However, authorities reported very slight or no damage, and the NYPD said no one was reported to be injured.

Video footage shows the earthquake interrupting a United Nations meeting:

According to the USGS, an earthquake occurs when two blocks of earth quickly slip past one another on the fault plane:

The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter.

…

The largest, main earthquake is called the mainshock. Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur afterwards in the same place as the mainshock. Depending on the size of the mainshock, aftershocks can continue for weeks, months, and even years after the mainshock!

Millions of people near New York City felt the earthquake, and many of their reactions were caught on video, per CBS Chicago.

“We saw the buildings moving and everything, though. It was kind of scary,” one woman told the outlet:

However, the report cited experts who said the earthquake was not powerful enough to “pose a threat to most buildings.” The outlet noted the epicenter was in New Jersey.