An earthquake of magnitude 6.4 struck central Croatia on Tuesday, killing seven people, injuring more than 20 and rattling several neighbouring countries, officials and residents said.

Rescuers pulled people from the rubble of collapsed buildings in Petrinja and other towns, and army troops were sent to the area to help.

Tremors were also felt in Croatia's capital Zagreb and as far away as Austria's capital Vienna. Slovenia shut its only nuclear power plant as a precaution.