Thus, Germany launched a military campaign in southeast Finland on 7 April 1918 with the landing of Detachment Brandenstein (German: Abteilung-Brandenstein) in Loviisa.

[1] As the Germans waited for reinforcements, they tapped enemy telephone lines and mistakenly believed that the Red Guards had a reserve of 10,000–30,000 soldiers heading to Kotka from the northern Kymi valley region.

[6] The next ten days were quiet, as the fighting was focused north of Loviisa in the Eastern Uusimaa region.

On 25 April, the Reds left their positions on the western side of the Kymi river and retreated across it, destroying bridges behind them.

[6] The Finnish Whites demanded an unconditional surrender, but according to the agreement concluded with the Germans, the individual soldiers were to be released and only the leaders made prisoners.

[5] The surrender became effective at midday of 5 May, as 800 Reds marched behind their commander Oskar Vinter towards the German lines on the western bank of the Kymi river.

After capturing the Reds, the Whites separated the staff members, platoon leaders and trade union activists from the crowd, and took them to the Svartholm fortress, where they were immediately shot.

The rest were kept overnight in the Vähä-Ahvenkoski village, and then transported to various White prison camps in Southern Finland.