Days after the hacking of the website and internal mails of the National Security Guard (NSG), the government Tuesday ordered temporary shutting down of the National Investigation Agency (NIA) site to tighten its safety mechanisms.

The webpage, http://www.nia.gov.in/, of the NIA says the site "is under maintenance".

The NIA, a premier anti-terror probe agency, was created in the aftermath of the 2008 Mumbai attack. It is empowered to take up terror-related crimes on its own across states in India without getting special permission from states.

Officials of the National Informatics Centre, which maintains all government websites, said that the site was "temporary" closed to "tighten security measures in order to prevent hacking".

The officials said that the step was taken following a detection of the hacking of the NSG internal mail that forced the elite commando force to suspend work on its internal mail system before an overhaul of security.

"We are reviewing the anti-hacking mechanism and the website will be back soon," an NIA official said.

Hackers in the past have targeted many Indian government websites, particularly of security agencies.

In December 2010, the website of the Central Bureau of Investigation (CBI) was hacked by a group who called themselves Pakistan Cyber Army.

The CBI had traced the hackers' portals to the US and Latvia.