It was a busy evening as usual on Monday near the Red Fort metro station in India's capital Delhi when the sound of a loud explosion broke the cacophony.

An explosion in a car killed at least eight people and injured more than 20. It was so powerful that several vehicles nearby almost melted, and people could hear the blast from kilometres away.

The police are still investigating what caused the blast but the fact that it happened in one of the most secure and busy areas of Delhi has shocked people.

On one side is Chandni Chowk - a busy trading and clothing hub that is busier than usual at this time of the year due to the peak wedding season.

And on the other side is the 17th Century Red Fort which attracts thousands of tourists every day.