Despite of the division being interim only, Poland decided to organise elections to the Polish parliament (Sejm) in the area. Czechoslovakia claimed that no sovereign rule could establish itself in the disputed area before determination of a definitive solution, and requested that the polls not take place in the area. Poland rejected the Czechoslovak request and Czechoslovakia attacked the Polish part of the region on 23 January 1919 and forced Poland, which was at that time in war also with the West Ukrainian National Republic over eastern Galicia, to withdraw from the western part of Cieszyn Silesia. After the fight near Skoczów a cease-fire was reached, signed in Paris on 3 February 1919. Poland had to recognize new borders running along the Olza River in 1920. Czechoslovakia received the western section (including the Karviná coal basin and the railway line) and smaller western part of the town, known later as Český Těšín, while Poland received the eastern section with Cieszyn and its historical centre.