On the 11th of April the Swedes sent 150 men under command of Lt. Baron Cederström to reconnaissance the road towards Nyen and to find the exact number of the opposing Norwegian force. The Swedes were spotted at Rønnesæter by a Norwegian field guard consisting of 30 ski soldiers. After some time the Norwegians were reinforced with soldiers from the Nordenfjellske Grenadier Company. The Swedes being outnumbered pulled back.
Two days later the Swedes returned with 200 men. This time they moved towards Nyen, but met subsequently stronger and stronger opposition since soldiers from both the Hoffske and Elverumske ski soldier companies as well as soldiers from the Sharpshooter division entered the area. The Swedes had to barricade themselves in the houses of a small nearby farm called Skalbukilen. The ski soldiers and the 2nd division of the Nordenfjellske Grenadiers attacked the Swedish position. The Swedes then being in danger of being encircled, pulled back across the border once more. Both Lt. Cederström and his second in command was wounded during this skirmish.
After the skirmish at Skalbukilen on April 13th the Swedes under col. Gahn did not make any further attempt to cross the border until the 24th April. On that evening Gahn received an order where he was told that the Swedes had been victorious at Lier and that he because of this should mount another attack. Late that evening the Swedes once more crossed the border. They marched for the whole of the night and at the break of dawn reached the farm of Utneset. At this place the road split in two, one followed the northern shore of the Flisa River and was the main road to the Glomma valley. The other road followed the opposite bank of the Flisa River and was regarded as a winter road (e.g. a road that is only passable when the earth is frozen). In the mean time the Norwegian forces had been warned of the approaching enemy and the soldiers were ordered to move towards Nyen. Col. Staffeldt, the Norwegian CO, was uncertain of which side of the river the Swedes would choose. Therefore one division of the Trønder Grenadiers had been ordered to man the hastily prepared timber barricades at the Trangen pass, while Staffeldt and his main force stood at the opposite side of the river. However it soon turned out that the Swedes had chosen to move along the winter road through the Trangen pass.
After a brief meeting with his officers Staffeldt decided that the best way to attack the Swedes was from the rear. The Ski soldiers and the sharpshooters were ordered to cross the river to attack the Swedish rear guard. This consequently led to the rear guard beeing driven out of its position at Gammelsæter and down to Gahn’s main force at Trangen. At the same time the Swedish avant guard was making contact with Captain Næglers division that was holding their positions in the Trangen pass. The Swedes were now under fire from two directions. They soon realized that the attackers from the North were the gravest danger and therefore headed their force in that direction to mount a counter attack. The Norwegian line started to break under the Swedish pressure, but was forced back into order by the officers. At the same moment Captain Nægler ordered his forces out of their position in the Trangen pass to attack the Swedes from the opposite direction. The Swedes soon realized that their situation was hopeless and had no other alternative than to try to break out of the Norwegian encirclement. The Swedes were inflicted heavy losses but didn’t manage to break out. Soon after came the final blow when the Hoffske Ski soldier company led by Captain Arntzen attacked from the third direction. The Swedes now considered the situation so hopeless that they decided to lay down arms.
Attacked simultaneously from three directions the Swedes are forced to surrender.
Elverumske Compagnie was together with Captain Næglers divison and 50 sharpshooters sent to Midtskogen to capture the rest of the Swedish rear guard. The Swedes were completely taken by surprise and didn’t make noteworthy resistance. This was hardly any surprise since most of the soldiers being wounded from the previous skirmishes at Nyen and Skalbukilen. The patrol returned the next day with 50 prisoners and two cannons. The most badly wounded Swedish soldiers where left at Midtskogen.
A total of 430 soldiers and 12 officers were captured, out of these 60 were wounded. More than 25 Swedes had been killed. Norwegian casualties were 15 killed and ca. 60 wounded.
The fallen from both sides where buried at Aasnes Church some days after the battle.