The office at the Slovenian Environment Agency (ARSO) said in a press release that the intensity of the quake reached level VI on the twelve-level European Macroseismic Scale (EMS).

Many residents of Pivka and the nearby towns of Ilirska Bistrica and Postojna left their homes following the event, while the kindergartens and the elementary school in Pivka were evacuated and the children sent home.

There are some reports of damage to the buildings, chiefly minor cracks and fallen plaster in the area between Pivka and Ilirska Bistrica, seismologist Matjaž Godec explained for the STA.

This has promoted the Seismology and Geology Office to upgrade the level of the quake from V to VI on the EMS scale, said Godec, adding that ARSO has received some 2,500 reports from locals about how they felt the quake.

The quake was however felt in the entire country, as well as in Italy's Trieste and Gorizia and Croatia's Rijeka and Zagreb. The latter is around 200 kilometres away from the epicentre.

According to the Croatian media, an earthquake of a similar magnitude, with the epicentre in Bosnia-Herzegovina, also shook the country some 25 minutes after the Pivka quake.

The latest earthquake of a comparable magnitude in Slovenia took place in December 2012, when the 3.9-magnitude earthquake with epicentre 30 km north-east of Ljubljana shook central and eastern Slovenia.

Earlier this month Slovenia marked 16 years since one of the strongest earthquakes in a century. A 5.6-magnitude quake claimed no lives but caused considerable material damage to the valley of the Soča river in the north-west.

The same area was hit by a 4.9 magnitude earthquake in July 2004, claiming one casualty, an Italian mountain climber.

However, the strongest earthquake in Slovenia over the past 100 years was in 1917, when the town of Brežice was hit with a 5.7-magnitude quake with intensity VIII on the EMS scale.