The arrondissements in the centre lost as much as twenty percent of their population, while the outer neighborhoods gained ten percent. The low birth rate of Parisians was compensated by a new wave of immigration from Russia, Poland, Germany, eastern and central Europe, Italy, Portugal and Spain. Political tensions mounted in Paris with strikes, demonstrations and confrontations between the Communists and the Popular Front on the extreme left and the Action Française on the extreme right.[177]