The pan-European Stoxx 600 index was down 0.2%, with most sectors in negative territory.
Autos and construction stocks each dropped 0.8%, while mining stocks rallied 0.9%.
European markets turned lower, after starting the new trading week on a positive note, as investors assess the turmoil in the Middle East.
Roughly 1.1 million Palestinians were given a 24-hour notice to evacuate northern Gaza last week and move to southern Gaza, but the order and deadline were heavily criticized by many humanitarian agencies.
Over the weekend, hundreds of thousands of Palestinians were trying to flee northern Gaza but the journey is hazardous and difficult.
Locations:
Gaza, Israel