In this paper, we argue that monetary policy in the form of central bank communication can shape long-term interest rates by changing risk premia. Using high-frequency movements of default-free rates and equity, we show that monetary policy communications by the European Central Bank on regular announcement days led to a significant yield spread between peripheral and core countries during the European sovereign debt crisis by increasing credit risk premia. We also show that central bank communication has a powerful impact on the yield curve outside regular monetary policy days. We interpret these findings through the lens of a model linking information embedded in central bank communication to sovereign yields.