India’s anti-terrorism agency said on Thursday it had arrested four more people, including three doctors, in connection with last week’s deadly car blast in Delhi, the first such attack in the heavily-guarded capital in more than a decade.

The car bomb killed 10 people and wounded 32 outside the historic Red Fort on November 10.

The four alleged “prime accused” have been identified as Dr Muzammil Shakeel Ganai, Dr Adeel Ahmed Rather, and Mufti Irfan Ahmad Wagay who come from Indian-occupied Kashmir, and Dr Shaheen Saeed from the northern city of Lucknow, the National Investigation Agency said.

“They had all played a key role in the terror attack,” the agency said in a statement on X, without going into more detail on their alleged involvement.

Ganai, Rather, and Wagay were previously in the custody of Indian-occupied Jammu and Kashmir police, who arrested them last week, saying “they were part of a terrorist unit linked to Pakistan-based militant groups Jaish-e-Mohammad and Ansar Ghazwat-ul-Hind.”

Their families denied that accusation at the time and said they were innocent.

Saeed’s brother did not respond to a Reuters request for comment on Thursday.

The NIA said that it had arrested two other people on Sunday and Monday. It named them as Amir Rashid Ali, in whose name it said the car was registered, and Jasir Bilal Wani, who it said allegedly provided technical help to alleged suicide bomber Umar Un Nabi, also a doctor.

The agency said that these three men also came from occupied Jammu and Kashmir.