Uppsala University seismologist Reynir Bodvarsson told the Swedish news agency TT he estimated the quake measured between magnitudes 4.5 and 5.0 on the Richter scale, saying, "It was likely felt in much of southern Sweden. For Sweden, this is a very strong quake."
"The bed shook for about 20 seconds," Helsingborg resident John O'Leary told The Local, adding that it woke him at about 6:20 a.m. and knocked over several items in his apartment.
The U.S. Geological Survey said the earthquake had a magnitude of 4.7, which, if accurate, would make it the strongest earthquake to hit Sweden in more than 100 years. An earthquake on Oct. 23, 1904, with an epicenter near the Koster Islands off Sweden's west coast reached a magnitude of 6.0, TT said.