The Ukrainian forces withdrew outside Lwów's confines by 21 November 1918, after which elements of Polish soldiers began to loot and burn much of the Jewish and Ukrainian quarters of the city, killing approximately 340 civilians (see: Lwów pogrom). The retreating Ukrainian forces besieged the city. The Sich riflemen reformed into the Ukrainian Galician Army (UHA). The Polish forces aided from central Poland, including General Haller's "Blue Army", equipped by the French, relieved the besieged city in May 1919 forcing the UHA to the east.