The Iranian IRNA news agency quoted the Health Ministry spokesman Kianoush Jahanpour saying that all forms of congregations must be canceled till further notice.
He added that 15 medical labs will be opened within next week to diagnose novel coronavirus infections.
On Wednesday, the ministry announced that four more people died in the country from coronavirus, bringing the death toll from the outbreak in Iran to 19.
Outside mainland China, the virus has spread to more than 30 countries, including the U.S., U.K., Singapore, France, Russia, Spain and India.
The World Health Organization has declared the outbreak an international health emergency.