At least 13 people are dead, including a police officer, as a result of nationwide protests in Iran. The demonstrations that began on Thursday have become the largest since the 2009 presidential election. Iranian President Hassan Rouhani sought to cool tempers on Sunday. He defended the people's right to protest peacefully, but warned that security forces would not tolerate vandalism and violence. CGTN's Jessica Stone reports.

According to Iranian police, a protester opened fire on police at a demonstration in the central city of Najafabad. Police say he used a hunting rifle. Three more officers were also wounded.

Demonstrations began Thursday in Northeast Iran (Mashhad). Protestors have specifically chanted against the government and its supreme leader, Ayatollah Ali Khamenei. They want their country to pull out of costly proxy wars with Saudi Arabia, and focus on rebuilding the national economy. Fuel and food prices are rising, as is unemployment.

On Sunday, Rouhani called on the protesters, and police, to remain peaceful.

HASSAN ROUHANI IRANIAN PRESIDENT "So the people have a right to criticize, all over the country. But, criticism is entirely different from violence and damaging public properties."

Adding Monday: "We should listen to this voice and turn it into an opportunity. We should see what the problem is and also what the solution is."