[1] Working on his own, Krarup conducted sporadic sabotage against German authorities in 1940; over the following years, his brothers Niels and Ulrik joined him.

On 4 October 1944, the Special Operations Executive agent Kjeld Toft-Christensen arrived from England and joined the group as a liaison officer and trainer.

L-group North initially comprised Hans Krarup Andreasen, Svend Ulrich Pedersen and Vagn Nørlund Christensen with Platou as group leader.

Sigurd Vestergaard Christensen, Jørgen Christian Jensen, Kjeld Toft-Christensen and Carl Johan Nielsen formed L-group Central, with Sørensen as leader.

Nørlund was subsequently sent to Vejle to start a new group, L-group South, with Svend Middelboe Jensen, to cover southern Jutland.