New Delhi, Nov. 12 -- Prime Minister Narendra Modi vowed on Tuesday that the conspirators behind the blast in Delhi that killed 13 people will be brought to justice, against the backdrop of investigators saying the car involved in the explosion was traced to a Kashmir-based doctor with ties to a terror cell linked to the recent seizure of a huge cache of explosives.

Addressing an event in Bhutan's capital Thimphu to mark the birth anniversary of the country's former king Jigme Singye Wangchuck, 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 authorities investigating the blast near the Red Fort.

"Today, I have come here wit...