Religion plays a significant part in the life of many Chinese. Buddhism is most widely practiced, with an estimated 100 million adherents. Traditional Taoism also is practiced. Official figures indicate there are 20 million Muslims, 15 million Protestants, and 5 million Catholics; unofficial estimates are much higher. While the Chinese constitution affirms religious toleration, the Chinese Government places restrictions on religious practice outside officially recognized organizations. Only two Christian organizations, a Catholic church without official ties to Rome and the 'Three-Self-Patriotic' Protestant church, are sanctioned by the Chinese Government. Unauthorized churches have sprung up in many parts of the country and unofficial religious practice is flourishing. In some regions authorities have tried to control activities of these unregistered churches. In other regions, registered and unregistered groups are treated similarly by authorities and congregations worship in both types of churches. Most Chinese Catholic bishops are recognized by the Pope, and official priests have Vatican approval to administer all the sacraments.