(SOURCE) Two women died when a wall of mud destroyed a house near the Swiss town of Lugano on Sunday.
Over the border, a pensioner and his granddaughter were killed when a mudslide engulfed their home.
The heavy rain is expected to continue across the region, and both countries have issued major flood alerts.
The levels of lakes Lugano and Maggiore, seen below, are already dangerously high.
Homes and businesses, such as this farm near Italy’s Lake Maggiore, have been cut off by rising waters.
The region has had more rain in a few days than it would normally expect in a year.
The Ticino river burst its banks near Vigevano in northern Italy.