“The group was planning to undertake terrorist attacks at vital installations in India with an aim to kill innocent people and strike terror in their minds,” the country’s main counter-terrorism arm said in a statement.
Those arrested “were motivated to undertake attacks at multiple places” including the capital region.
Six of the militants were arrested in the eastern state of West Bengal and while three in the southern state of Kerala, the NIA said, adding the individuals were “associated with Pakistan sponsored module of al Qaeda”.
A spokesman for Pakistan’s foreign office did not immediately respond to a request for comment. Pakistan has often denied giving material support to militants.
India has stepped up an offensive against militants in the Muslim-majority region of Kashmir and elsewhere.
Last year, Indian forces killed the leader of an al Qaeda-affiliated militant group in Kashmir, triggering protests in parts of the disputed region.
In the latest raids, the NIA seized sharp weapons, domestically made firearms and locally fabricated body armour. The nine militants will be produced in court for police custody and further investigation, the agency said.