A measure tightening registration rules for faith groups in Kazakhstan was signed into law by President Nursultan Nazarbayev this week.
The law has been described by critics as a blow to freedom of religion in the ex-Soviet nation, which was once touted by Nazarbayev as a land of religious tolerance.
Supporters say the measure will help combat religious extremism. A series of Islamist-linked attacks over the summer have drawn concern in the country.
The law requires existing religious organizations in the mainly Muslim nation to dissolve and register again.
It could also make it extremely difficult on minority Christian communities, since they may not be officially recognized by the state.
To register locally, a faith group must now be able to provide evidence of 50 members. To register at a regional level requires 500 members.
The most complicated procedure will be registering nationwide, which requires a group to have 5,000 members across the country's regions.
"Several minority religious groups do not have the required number of members and would be prohibited from continuing their activities and subject to fines if they disobey," the Washington-based democracy watchdog Freedom House said in a statement last month.
Felix Corley, editor of the Norwegian-based religious freedom group Forum 18, said a separate law also signed Thursday amends legislation on religion to broaden the range of offenses subject to punitive action.
"These two new laws. undermine everyone's freedom of religion or belief and, as local human rights defenders have pointed out, are part of a wider picture of increasing governmental controls on society," Corley told The Associated Press.
The bill also imposes a ban on prayer in the workplace.