New Delhi: A hacking group said it attacked the Mahanagar Telephone Nigam Limited (MTNL) website, accusing the company of censoring content on the Internet.
The corporate website of MTNL, which caters to the major Indian cities of New Delhi and Mumbai, was down for at least six hours. A post on hacking group Anonymous India's blog said the company was attacked because it had blocked several file sharing websites.
But MTNL officials denied any knowledge of an attack.
Anonymous India said it attacked the MTNL website accusing the company of censoring content on the Internet.
"We have individual websites for Delhi and Mumbai ... and both are operational," said MK Purohit, general manager of broadband services at the company's Mumbai office.
Purohit said the company's corporate website - the site Anonymous said it had hacked - was no longer in use. But an online search for the domain's owner showed MTNL as the registrant until February 2014.
Earlier this week, Anonymous India claimed to have taken down the website of the Internet Service Providers' Association of India. The association's president, Rajesh Chharia, denied an attack had occurred.
The Indian hacker group is a spinoff of Anonymous, an amorphous group of activists, hackers and pranksters whose past targets have included Visa and MasterCard.
Anonymous cut its teeth with attacks on the music industry and the Church of Scientology but has lately turned its focus to law enforcement, intelligence and military-related sites.
The claimed hacks this week come just days after an online press conference at which Anonymous announced the launch of "Operation India," a protest movement against Internet censorship. The movement, modeled on the lines of the Occupy Wall Street protests, is meant to be spread across 19 cities in India, starting June 9.
In recent months, the group has targeted several Indian websites, ranging from those of government agencies and political parties to private ISPs and other corporate groups.