Leighton Buzzard residents have felt a second earthquake within a week.
The British Geological Survey (BGS) said a 2.1-magnitude tremor was felt in the Bedfordshire town at 00:20 BST on Monday.
It comes after a 3.5-magnitude earthquake hit the town on Tuesday.
The BGS tweeted there had been “a small number of reports” from the public with one saying this earthquake “felt slower and less intense”.
One Twitter user said: “What is going on??? Just woken by another earthquake in Leighton Buzzard!”
Leighton Linslade Town Council mayor Dave Bowater said he slept through the second quake, but the first had been “a little bit frightening”.
“We’ve had two now and the experts say that is one and the aftershock,” he said. “We should be done now.”
Mr Bowater, who once spent 10 days living on the 14th floor of a hotel in Tokyo while a number of four and above-magnitude earthquakes took place, said he was surprised to experience two in Leighton Buzzard.
“It brings things sharply into focus when you can be hit that strongly out of the blue,” he said.
struck just north of Leighton Buzzard and was also felt in Dunstable, Bedfordshire, and Milton Keynes and Aylesbury in Buckinghamshire.
A BGS spokesman said the second tremor was more than 100 times smaller than the first.
He said it “could have occurred because all the stress in the rocks was not relieved” or because the first earthquake “caused a slight change to the stress regime in that location”.