Iran\'s currency, the rial, slumped six percent in street trading Monday, accelerating a slide triggered on the weekend when the United States activated new sanctions over Tehran\'s nuclear drive. The rial was being exchanged for 17,000 to the dollar late Monday. Before US President Barack Obama on Saturday signed into law the new sanctions targeting Iran\'s financial sector and central bank, the rial was trading around 15,500 to the dollar. The European Union is mulling its own additional sanctions, including a possible embargo on Iranian oil imports. If those are decided at an EU foreign ministers\' meeting at the end of this month, Iran\'s rial could show further strain.