Following raids in West Bengal and Kerala, the National Investigation Agency (NIA) on Saturday arrested nine militants linked with the Al Qaeda terror group, who were planning attacks at several key installations in Delhi-NCR, a spokesperson said.

The NIA spokesperson said that the anti-terror probe agency carried out the simultaneous raids at several locations in Kerala's Ernakulam and West Bengal's Murshidabad after learning about an inter-state module of Al Qaeda operatives at various locations in India.

"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 spokesperson said, adding that it has registered a case on September 11.

The official said that NIA has arrested six terrorists from West-Bengal and three from Kerala in the early morning raids.

During the raids, large quantity of incriminating materials including digital devices, documents, jihadi literature, sharp weapons, country-made firearms, a locally fabricated body armour, articles and literature used for making home-made explosive devices have been seized from their possession.

"As per preliminary investigation, these individuals were radicalised by the Pakistan-based Al Qaeda terrorists on social media and were motivated to undertake attacks at multiple places including the National Capital Region," the official said.

The official said that the module was actively indulging in fund raising and a few members of gang were planning to travel to New Delhi to procure arms and ammunition.

However, these arrests have pre-empted possible terrorist attacks in various parts of the country.

Arrested terrorists have been identified as Murshid Hasan, Iyakub Biswas and Mosaraf Hossen, all three residents of Ernakulam.

Najmus Sakib, Abu Sufiyan, Mainul Mondal, Leu Yean Ahmed, Al Mamun Kamal and Atitur Rehman, all residents of Murshidabad.

The official said that they will be produced before the concerned Courts in Kerala and West Bengal for police custody and further investigation.