The four Bofors guns were massive for vessels of this size, and they could hurl a shell up to . The secondary artillery consisted of eight dual-purpose Bofors guns in four turrets. These were the primary defense against fast torpedo boats and aircraft. Additionally, the ships were equipped with four 40 mm anti-aircraft guns (initially British-made "pom-pom" guns, which, after mediocre performance in the Winter War, were replaced with Bofors guns) and two Madsen 20 mm cannons (later increased to eight).