In spring 617, Li persuaded Zhai that, with Emperor Yang away and his grandson Yang Tong the Prince of Yue in charge at Luoyang, the officials there were not of one mind. They thus sent Pei Shufang () to Luoyang to scout it, but Pei was discovered, and the Sui officials at Luoyang began to prepare for an attack. In response, Li and Zhai launched their assault at Luokou Storage (), a massive food storage that Emperor Yang built, and they captured it.
In spring 617, Li convinced Zhai that, with Emperor Yang absent and his grandson Yang Tong the Prince of Yue in charge at Luoyang, the officials there were not united. They thus dispatched Pei Shufang () to Luoyang to investigate, but Pei was found out, and the Sui officials at Luoyang began preparing for an assault. In response, Li and Zhai launched their attack on Luokou Storage (), a large food storage that Emperor Yang constructed, capturing it.