The offending Web site was found to promote antinational news, the government's Department of Telecommunications said in a statement Monday. The Web site contained material regarding the federal government and the local government of Meghalaya, a state in northeast India. Many insurgent groups are active in the region.
The department said it ordered the site blocked after Yahoo officials in India declined to comply with a request to remove the material from the Web site.
Yahoo did not immediately respond to requests for comment.
In July, the government's Department of Information Technology established the Indian Computer Emergency Response Team (CERT-In) under the provisions of the Indian Information Technology Act 2000. The government said one of the jobs of that body would be to ensure a "balanced flow of information"--not censorship.
Internet censorship has become a controversial international topic, with regimes in China and Myanmar trying to restrict information over the Net. The U.S. House of Representatives approved legislation in July. It would have the unusual mission of devising technical methods to prevent other nations from censoring the Internet.
However, in the United States itself, there have been attempts to block Web sites. A Pennsylvania state law, which took effect last year, permits the state's attorney general to order Internet service providers to block access to the IP address of sites that are suspected of featuring child pornography. Two civil liberties groups that challenged this law won aearlier this month from the Pennsylvania attorney general, who agreed to cease using the orders until the case is heard in November.
This is the first such case of Internet regulation in India, and experts say it raises censorship concerns.
"While the inherent sovereign powers of the government to block can hardly be denied, the manner and procedure in which it has been done is not on sound legal grounds and is liable to be legally challenged in a court of law," Pavan Duggal, a cyberlaw analyst, said in an interview.
Duggal said the government rules under which the ban has been imposed are one-sided and give no effective legal remedy for blocked Web sites.
"The government has to be extremely careful in proceeding with the process of blocking, as it can be seen as a form of censorship."