Four mines, the largest yet sprung by the British, were detonated on 2 March, then followed up by two battalions of infantry, which captured the new craters, several German occupied craters, Triangle Crater that had been unknown to the British. The main entrance of the German mine galleries was discovered in the crater and the 170th Tunnelling Company crossed no man's land to demolish the entrance. German counter-attacks concentrated on the recovery of Triangle Crater, which was re-captured on 4 March. The recovery by the Germans of the gallery entrance threatened the positions captured by the British, who attacked Triangle Crater on 6 March but were repulsed. British tunnellers got into the German gallery system from a British tunnel and were able to demolish the system on 12 March, which relieved the threat of another German mine attack. Skirmishing around the craters diminished and it was thought that the Germans were concentrating on consolidating new positions.