Homes shook in Crawley after an earthquake struck – the latest in a series of tremors in the area.
People reported the quake in the early hours on social media, with one Twitter user posting: “Did an earthquake just happen in Crawley? My whole flat just shook underneath me!”
It follows a series of tremors in the area – four were recorded in February.
An area just over the Sussex-Surrey border has been in the grip of an earthquake “swarm” since last year.
The British Geological Survey (BGS) has been monitoring the quakes and has said the epicentres are tightly clustered in a small source zone between the villages of Newdigate and Charlwood, near Gatwick.
The latest tremor at 01:19 BST, which had a 2.5 magnitude, has been recorded on the BGS website.
A BGS spokeswoman said: “Around 100 reports from members of the public in the epicentral area have been received so far and many others have taken to social media to report their experience.”
She said typical reports described doors and windows shaking, while one said it “felt like some sort of explosion” and another said “a loud bang woke me up”.
Concerns were raised earlier this year the tremors were the result of nearby oil and gas exploration.
Stephen Hicks, a seismologist at Imperial College London, has said that scientists are keeping an open mind.
He said: “It is most likely that these earthquakes are natural, due to small tectonic stresses occurring on old geological faults caused by stresses from our nearest plate boundaries in the Mid-Atlantic and Mediterranean.”