A dozen mainstream journalists were arrested briefly in August presumably to prevent the reporting of tribal clashes in the north. Crackdowns are permitted under the National Security Act, the Official Secrets Act, and the Restricted Areas Act. Newspapers are required to register with the government and authorities are permitted to close papers. The government promised early in the year it would review the press laws to ease controls. Nine newspapers appear daily and many others less regularly. Some are linked to political parties. Papers, including some state-owned, criticize official policies. The government allows private radio and television operators, although the independent media sector exercises a strong degree of self-censorship. Most Tanzanians get their news from radio.