Another uneventful advance into the North Sea took place on 21–22 April. A bombardment mission followed two days later; "Posen" joined the battleship support for Hipper's battlecruisers while they attacked Yarmouth and Lowestoft on 24–25 April. During this operation, the battlecruiser "Seydlitz" was damaged by a British mine and had to return to port prematurely. Due to the poor visibility, the operation was soon called off, leaving the British fleet no time to intercept the raiders.