Hail of the size of tennis balls poked holes in cars and roofs in Slovenia and Croatia, while the overnight storm that engulfed the region knocked down trees and electricity in Bosnia.

Strong winds and heavy rain started Friday evening and stretched through the night, causing trees to fall over roads and roofs.

Bosnian Firefighters had to clear the regional road M4 near Tuzla, and in Srebrenik from fallen trees. One tree fell on the roof of a primary school in Maglaj.

Electricity was knocked out in Livno, Tomislavgrad, Drvar and in villages around Trebinje in the south of Bosnia and Herzegovina.

Authorities said power will be restored during the day.

Most of the rainfall was recorded in Bileca, in the southeast, where 121 liters fell per square meter.

Emergency teams are pumping water out of several ground floor apartments but no substantial damage has been reported.