AlQa'dah 4, 1434, Sep 10, 2013, SPA -- Police say four people were killed and 14 injured in the second deadly explosion to strike southern China in two days, AP reported. The blast Tuesday set huge plumes of smoke pouring from a fire in a garage in an industrial park in the commercial hub of Guangzhou. Police said the cause was under investigation, although media reports said it appeared to have originated with explosive materials being stored at the site. The blast follows one Monday on a busy street outside a school in the southern resort city of Guilin that killed two people and injured 17, including 10 students. That was believed to have been caused by the detonation of explosive materials being transported aboard a flatbed tricycle and city authorities ordered a safety crackdown in its wake.