the slow advance in the south, Arnim wanted the 1st Army to withdraw to Wadi Akarit on 25 March but Liebenstein and Messe preferred to counter-attack with the 15th Panzer Division. The threat to Maknassy and the possibility of the II US Corps reaching Gabès and cutting off the 1st Army, meant that they had to retire from Mareth and then from Tebaga. Height 184 fell at to the 21st New Zealand Battalion and the Allied artillery commenced firing at . The attack began with the 8th Armoured Brigade, followed by infantry battalion carriers and then infantry on foot. It appeared that the 164th Light and 21st Panzer divisions had not expected a daylight assault and had been surprised; the setting sun, wind and dust had made observation difficult. The British tanks had been ordered to press on and the infantry also managed a quick pace, arriving on the first objective and then kept going, despite increasing resistance and delays. An armoured regiment pressed on to Wadi Aisoub beyond the second objective, followed by the 23rd New Zealand Battalion. On the left, a minefield covered by anti-tank guns was bypassed on both sides to close up to the second objective, clearing a gap for the 1st Armoured Division, despite many Axis posts holding out in the vicinity. By dark a gap in the defences had been made; pausing until moonrise at the 1st Armoured Division advanced through the gap and rapidly moved on El Hamma, to the north-east, halfway to Gabès on the coast. On the morning of 27 March, the 15th Panzer Division was brought out of reserve to counter-attack the New Zealand Corps on their right flank. By the attack had been repulsed and the New Zealand Corps advanced into the hills on their right. By the evening of 27 March, German resistance had been broken and the line of communication forward to the 1st Armoured Division secured, the division having been halted by the defences of El Hamma, while the tanks had waited for the moonlight. Freyberg persuaded Horrocks that the New Zealand Corps, en route to El Hamma to link with the 1st Armoured Division, should branch off to the right to avoid the Axis defences at El Hamma and head across the broken ground direct to Gabès. By 28 March, General Messe gave the order that all Axis forces on the Mareth Line be withdrawn