Investing.com -- Crude oil prices tumbled on Friday after The Wall Street Journal reported that Saudi Arabia had agreed to a partial ceasefire in Yemen, where its forces have been leading a coalition against Houthi rebels since 2015. The news appears to reduce the risk of further military action between Saudi Arabia and its allies on the one side, and the Houthis and their backers in Iran on the other side. Saudi Arabia had blamed Iran for the drone and missile strikes that partially disabled key Saudi oil infrastructure earlier this month.