The loss after just six hours of a position held by the Legion galvanized the French general staff in Hanoi. On the 14th, the 5th Bn. Para Vietnamese was dropped to reinforce the garrison. On the evening of the same day, at 6:00 p.m., the bombardment of the "Gabrielle" strongpoint, occupied by Algerian riflemen supported by eight 120 mm mortars of the Legion, began. During a whole night of desperate fighting, eight Bns. of the Viet Minh rushed to attack this single battalion. At dawn, only one position was still in the hands of the French, and a counter-attack executed by two Companies. of the Legion and a Bn. Vietnamese Para, supported by six tanks, allowed to recover the 150 survivors of "Gabrielle".
There was then a lull in the attacks, each of the two parties regrouping their forces and establishing new positions, the French for the purpose of defense and protection, the Viet Minh to close in on the enemy. On the 16th, the men of 3rd Bn. Thais abandoned their "Anne-Marie" positions and, at the same time, several hundred North Africans and Vietnamese dispersed and, having become "internal deserters", sought refuge in underground hiding places which they dug on the banks of the Nam Yum River.
However, although casualties were caused by enemy effect and desertion, reinforcements also joined the garrison. From March 16 to 27, the 6th Bn. of colonial paratroopers commanded by the legendary Lieutenant-Colonel Marcel Bigeard, a field hospital, an artillery detachment, as well as 400 volunteers who were making their first jump, were parachuted into Diên Biên Phû. At the beginning of April, they were followed by two Companies. of the 2nd Bn. of the Legion commanded by Lieutenant-Colonel Brechignac, then by the 8th and 5th Bns. of colonial paratroopers, the first being under the command of Lieutenant-Colonel Guiraud. There were now seven Bns. Para in the valley. The command had been devolved to paratroop officers, headed by Lieutenant-Colonel Langlais. His relations with the nominal leader, Colonel de Castries, were always good, but one wonders if the tough Breton parachutist would not have been better off in this position than the elegant cavalry officer.