On Sep 30 1944, the Allied Control Commission handed an ultimatum to the Finnish Government stating something like that "the RKKA is more than ready to aid in pushing the Germans out of Finland". You see, Finns had agreed in Moscow in early September either to intern or expel the German troops starting on Sep 15.
However, there was a so-called gentleman's agreement between the two former brothers in arms that when the Germans started retreating the Finns just followed them, not trying to engage. A story tells, too, that the Finns had agreed not to re-build the bridges to carry heavy trucks or AFVs.
Fortunately, the Finnish military had already planned an invasion setting the D-Day on Oct 1. At first the main target was suppsed to be the town of Kemi, but after some data leaks a re-consideration took place and the target was changed to be Tornio. In the pic we see a Finnish convoy steaming towards Tornio, and for obvious reasons it's taken on Oct 3.
Interesting details:
When the vessels were loaded in the Port of Oulu the cranes couldn't lift field artillery, meaning that the heaviest weapons of the 1st wave were 45 mm AT guns and 120 mm mortars.
Also they lacked the maps of the invasion area. Fortunately there were phone booths from where the maps were taken - and as the city was not evacuated, local civilians were used as guides. As far as I know, the Tornio Battle is the only where the attacking units had to advance on their own soil without proper maps.
SA-kuva pic # 165139.