Iranian link to IED blast near Israeli embassy in New Delhi?

Hours after a low-intensity improvised explosive device went off near the Israeli embassy in New Delhi, investigators have picked up vital clues from the incident spot. Here's what we know so far. 

* Indian and Israeli security agencies are probing the possibility of the involvement of Iranians or a local ISIS module.
 

* Delhi Police Special Cell has obtained CCTV footage showing a cab dropping off two persons who walk towards the spot near Israel Embassy where the explosion occurred on January 29. 
 

* The Delhi Police Special Cell has contacted a cab driver, who was seen dropping two persons near the embassy in CCTV footage. Any role of these persons in the explosion is yet to be ascertained.

* A letter in an envelope has been found near the blast parameter outside the Israeli Embassy. The letter was reportedly addressed to the Israeli Ambassador. 
 

* Sources say that a letter that was recovered from near the embassy was apparently written by Dr Mohsen to the Israeli Ambassador Ron Malka mentioned the killing of top Iranian Military officer Qasem Soleimani and Iranian Nuclear scientist Mohsen Farkhrizadeh.
 

* Calling the blast a "trailer", the letter is believed to have warned the Israelis that their lives could be 'ended anytime'.
 

*  Israel Ambassador to India Dr Ron Malka shared a video message after the blast. Confirming that mission diplomats and employees are safe, Malka said, "We are working with Indian authorities to find the perpetrators and the motive behind the attack".

* Home Minister Amit Shah called off West Bengal visit today in view of the blast outside Israel Embassy in New Delhi. Home Minister likely to meet top security and intelligence officials today. 
 

* Delhi Police sources said that ammonium nitrate was used to carry out the IED explosion.
 

* The blast took place when President Ram Nath Kovind, Vice President M Venkaiah Naidu and Prime Minister Narendra Modi were present a few kilometres away at the Beating Retreat ceremony at the culmination of the Republic Day celebrations.