In spring 1928, the Central Committee ordered Mao's troops to southern Hunan, hoping to spark peasant uprisings. Mao was skeptical, but complied. Reaching Hunan, they were attacked by the KMT and fled after heavy losses. Meanwhile, KMT troops had invaded Jinggangshan, leaving them without a base.[103] Wandering the countryside, Mao's forces came across a CPC regiment led by General Zhu De and Lin Biao; they united, attempting to retake Jinggangshan. Initially successful, the KMT counter-attacked, pushing the CPC back; over the next few weeks, they fought an entrenched guerrilla war in the mountains.[101][104] Central Committee again ordered Mao to march to south Hunan, but he refused, remaining at his base. Contrastingly, Zhu complied, leading his armies away; the KMT attacked Mao's base, and although his troops fended them off for 25 days, Mao left the camp at night to find reinforcements. Reuniting with the decimated Zhu's army, they returned to Jinggangshan and retook the base. Joined by a defecting KMT regiment and Peng Dehuai's Fifth Red Army, the mountainous area was unable to grow enough crops to feed everyone, leading to food shortages throughout the winter.