India, Nov. 11 -- Prime Minister Narendra Modi pledged on Tuesday that the conspirators behind the blast in Delhi that killed 13 people would be brought to justice, even as investigators said the car involved in the explosion was traced to a Kashmir-based doctor with ties to a terror cell linked to the seizure of a huge cache of explosives in Faridabad.

Addressing an event at Changlimethang Stadium in Bhutan's capital Thimphu to mark the 70th birth anniversary of the country's former king, Modi said he was committed to participate in the important occasion but had come with a "heavy heart". He said he had spent most of Monday night coordinating with agencies investigating the blast that occurred near the Red Fort.

"I have come here with...