Indian authorities announced on Sunday the arrest of a man who they believe to be involved in a car blast in Delhi last week, where 10 people were killed and at least 20 were injured.

Officials said they were treating the blast as a "terrorist incident," caused by a "suicide bomber."

They have identified the driver of the vehicle that exploded as a resident of Kashmir. The man is believed to be an assistant professor in general medicine at a university in the northern state of Haryana.

Control over the territory of Kashmir has been divided between Pakistan and India, which have disputed it since the two countries were formed in 1947.

The car explosion in Delhi took place near a busy metro station near the Red Fort, one of India's best-known landmarks and a major tourist attraction. 

Alleged 'accomplice' arrested

Indian Prime Minister Narendra Modi said the attack was a "conspiracy," vowing to bring the "perpetrators, their collaborators and their sponsors" to justice.

India's anti-terror bureau, the National Investigation Agency (NIA), said the arrested suspect was an accomplice to the driver and that his detention marked "a breakthrough" in the investigation.

The car involved in the attack was registered in the name of the suspect arrested on Sunday.

He is said to have traveled to Delhi from Kashmir to "facilitate the purchase of the car which was eventually used as a vehicle-borne improvised explosive device (IED) to trigger the blast," a statement from the counter-terrorism agency read.

The explosion near Delhi's historic Red Fort is the first incident of mass violence to take place in the heavily guarded city since 2011.

Edited by: Sean Sinico