Officials said the hacking attempt was noticed early on Sunday and the URL - www.nsg.gov.in - was blocked soon after by the counter-terror force from its headquarters in New Delhi.
The hackers, identifying themselves as 'Alone Injector', posted the offensive content on the site's home page.
Official sources said the hacking attempt could have been carried out by Pakistan-affiliated hackers, though they were still trying to ascertain exact details in this regard.
The elite commando force was raised in 1984 as the federal contingency unit to undertake counter-terror and counter-hijack (rpt) counter-hijack operations.
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