Monday’s blast targeting an Israeli diplomatic vehicle is the first instance of collaboration between militants here and an external group that could well be Hezbollah.

This emerged during a conference call Tuesday between Intelligence Bureau director Nehchal Sandhu and Israel’s Mossad chief Tamir Prado. The Indians told the Israelis while there was no clear evidence of Hezbollah operating here, outfits like Lashkar-e-Tayyaba and Indian Mujahideen were sympathetic to Hezbollah and had targeted Jewish and Israeli interests earlier. Mossad has provided a crucial lead: an “extremely sophisticated switcher was used to trigger the magnetic explosive” — of a kind not used in India earlier. The NSG has indirectly corroborated this.