Investigators conducted searches for a red motorcycle used by the attacker for sticking the bomb on the Toyota Innova car used by Israeli diplomat on Monday and found one in south Delhi's Lado Sarai but is yet to link it with the incident.
Iranian Ambassador to India Mehdi Nabizadeh said that his country would neither accept nor deny Israeli allegation that Tehran was behind the attack on its diplomat here and hoped that New Delhi will verify the case and clarify the real position.
A nine-member team from Israel embassy also inspected the cars which were damaged in the sticky bomb explosion in which the diplomat, Tal Yehoshua-Koren (40), and three others, including her driver, were injured.
The team visited the Special Cell office in south Delhi's Lodhi Colony this afternoon and inspected the car in which the she was travelling. They also inspected another car which was damaged.
Sources said 250 to 300 grams of explosives were used in the bomb that targeted the car.They said Delhi Police is coordinating with Israeli investigators through the country's Embassy here and have launched a hunt for the red bike which the attacker used.
Sources said they were also looking into the attack on an Iranian nuclear scientist on January 12 in Tehran in which he was attacked in a similar fashion.
In both cases, a motorcyclist stuck a bomb on the vehicle they were using, sources said.
CCTV footages scanned so far have not provided any help in tracking down the vehicle and the person riding it.
Investigators yesterday recovered magnetic pieces from the device used for exploding the bomb and were awaiting the report of the Central Forensic Sciences Laboratory (CFSL).
Police have also started the process of collecting details of Iranians living in the capital.
Five persons owning red coloured motorcycles were detained yesterday but were let off later while another person who was caught on CCTV in front of Israeli embassy appeared before investigators but turned out to a courier.
The NSG has alerted all its commando squads guarding VVIPs and will soon bring out new security drills following Monday's attack.
"We have already alerted our people (guarding VVIPs) that this is what has most likely happened and immediate action we have taken...but this is not enough. We have to really study it (the February 13 incident here) and make a standard operating procedure so that everybody acts in a uniform way (during such an attack)," NSG Director General R K Medhekar said in Manesar.