The quake, which hit at 6.20am (1.20pm Singapore time), had its epicentre some 59 kilometres (36 miles) southeast of Sweden's third-largest city Malmoe, the institute said.

Media reports indicated the shock was felt throughout southern Sweden and northern Denmark, including the Danish capital Copenhagen, as buildings and homes shook but no damage was reported.

Earthquakes of this magnitude are rare in Scandinavia.

'For Sweden this is a very big quake,' Reynar Boedvarsson of the Seismological Institute told Swedish news agency TT.

'It's not dangerous for people but there may be cracks in building constructions,' he said. -- AFP