There was no immediate comment from Iran or Hezbollah. But speculation will undoubtedly be raised over the possibility of Iranian-linked payback for assassinations on nuclear scientists and other covert plots that Tehran has blamed on Israel's spy agency Mossad and Western allies.
"There have been all kinds of mysterious things happening in Iran, and it could be an Iranian counterattack," said Mike Herzog, a retired Israeli general and former top aide to Israeli Defense Minister Ehud Barak. "It's no secret that Iran uses Hezbollah globally, and Hezbollah has the capacity to carry out attacks around the globe."
Hezbollah dominates the government of Lebanon, which borders Israel to the north.
Were Iran behind the New Delhi attack, it would be a stunning violation against one of its stronger allies.
Indian Prime Minister Manmohan Singh has resisted U.S. and EU pressure to curtail trade with Iran over the nuclear issue. Energy-starved India relies heavily on Iranian oil imports and the two countries are working to find creative ways for India to pay for the oil by using rupees and investing in Iranian infrastructure projects.
Image: Indian security and forensic officials examine a car belonging to the Israel Embassy after an explosion tore through that, injuring two people in New Delhi on Monday.