A small earthquake woke residents as it sent shockwaves across north-east England.
The 3.0 magnitude quake hit near Alberto Street in Stockton-on-Tees in County Durham at 5.56am on Thursday, according to the British Geological Survey (BGS).
On the Richter scale, an earthquake of that size is likely to be felt by some people, but is unlikely to cause damage to any buildings.
The United States Geological Survey (USGS) initially estimated the magnitude of the quake at 2.8 but that was revised upwards by the BGS to 3.0 following local analysis.
BGS seismologist Glenn Ford said the shaking would have lasted for a few seconds, and could have been strong enough to knock over ornaments in people’s homes.
He said there were usually just three 3.0 magnitude earthquakes in the UK every year, compared with around 100,000 elsewhere in the world, with even more stronger ones recorded globally.
Mr Ford said: “We are not terribly seismic in the UK, people are just not calibrated to them.
“People would not have looked up from their newspaper for this one if this happened in Greece.”
Residents tweeted about what they felt as the tremors hit the region.
One person said that their house was shaken by the incident, adding that it was "bad enough to wake us up”.
A fellow user said that it shook their house "as if a train went past my bedroom window”.
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Another posted that it was a "strong earthquake (for England)", saying that the "whole house shook and electricity flickered”.
"Wow that's a first, felt an #earthquake in Stockton around 6am this morning", one user said.
Some residents at first believed the noise from the quake was an “explosion” – but turned out to be tremors.
Gillian Foster, watch manager at Cleveland Fire Brigade, told Mirror Online: “We turned out to a report of a potential explosion at a bungalow.
“Neighbours were out and felt same thing – some kind of explosion.”
The USGS said that 139 reports on the shake had been received from the public.