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. Sandwiched between the two is the road where the explosion took place. Within minutes, confusion and alarm spread from the scene to the rest of the city. Mohamed Hafiz, who lives less than 200m from the spot, said his house shook and he and others ran out thinking it was an earthquake. What he saw on the street terrified him: people were running in all directions, cars were on fire, and bodies lay on the road. Some locals were trying to help the injured.  "There was blood everywhere. People were in shock. The scene was too disturbing - I could even see body parts," he said. As local media broke the news, fear and panic swept through the city. Police declared a high alert, and neighbouring states quickly followed suit. (BBC)