At least 17 people were killed Saturday and another 10 trapped after a coal mine explosion in northern China, just days after a similar incident left 21 miners dead in a separate region. State media said four miners were rescued immediately after the blast in the Inner Mongolia region. Thirty-one people were underground at the time of the explosion. The state-run Xinhua News Agency said rescuers were searching for the other 10 miners who remained trapped in the mine run by Baoma Mining Co. Ltd. The news of the blast came just hours after 21 miners were confirmed dead in a separate incident in Heilongjiang province. Four people were arrested in connection with that explosion, which occurred in an unlicensed coal mine.