A day after a car bomb attack injured four people including an Israeli diplomat in the heart of Delhi .The police have started scouring for possible leads from CCTV footage.Officials of the National Investigation Agency (NIA) also surveyed the blast spot today. Meanwhile, the Home Ministry held a review meeting today. Home Minister P Chidambaram discussed preliminary investigations into the blast with senior MHA officials. Security at Jewish and Israeli establishments in the city, like Paharganj, has been beefed up.