Fighting spread with the Red Guards beginning the seizure of Helsinki on the night of January 27/28. White forces headed by General Mannerheim controlled the northernmost five-sixths of Finland, while the Reds controlled the southernmost region, containing approximately half of the country's population and including the cities of Pori, Turku, Tampere, Riihimäki, Helsinki, Kotka, and Viipuri. A Finnish Revolutionary Government was declared, in which Sirola served as Commissar of Foreign Affairs.