The hit squad behind last week’s deadly attack on the man long thought to be the mastermind of Iran’s alleged military nuclear program left nothing to chance. As nuclear scientist Mohsen Fakhrizadeh’s black Nissan sedan car approached a boulevard in the Damavand region, about 60km from the capital Tehran, an automatic machine gun, installed inside a blue pick-up truck parked under an electric transmitter, began firing.

The pick-up truck, packed with explosives, was then detonated by remote control. Assailants then opened fire, according to Fereydoon Abbasi-Davani, a nuclear scientist who survived an attempt on his life in 2010, and domestic media. Javad Mogouei, a documentary maker close to hardliners, said there were as many as 12 attackers, including those on motorbikes, in a Hyundai SUV as well as hidden snipers.

Iran has blamed Israel for the assassination of Fakhrizadeh. The dramatic attack at the heart of the regime has escalated tensions in a fraught period as US president Donald Trump prepares to make way for president-elect Joe Biden, who is keen to restart talks over the 2015 nuclear deal between Iran and global powers.

Mr Trump abandoned the historic accord under the accord. Iran has always denied that it has a military nuclear program but successive Israeli governments have accused Tehran of trying to develop an atomic weapons capability.

Israel vehemently opposes the resumption of talks between the Islamic republic and the US. Iran has promised revenge for what it called a state act of terror.

Iran has never taken direct action against Israel and President Hassan Rouhani said this revenge would happen “at the right time and appropriately” but that Iran was “intelligent and wise enough not to be trapped in the Zionists’ plot”.

This is the second high-profile assassination this year after an American drone killed Iran’s most powerful military commander Qassem Soleimani in

Baghdad. In the wake of that attack, Iran fired missiles at an Iraqi base hosting US troops but there were no deaths.

The head of Iran’s defense ministry’s Organization of Defensive Innovation and Research, Fakhrizadeh was a shadowy figure.

Few pictures of him are available in domestic media and there are hardly any records of public speeches. Most Iranians first heard of him when the US put him on the sanctions list in 2008.

In May 2018, after Israeli intelligence agency Mossad made public that it had spirited away Iran’s nuclear archives from a warehouse in Tehran, Prime Minister Benjamin Netanyahu publicly pointed to  Fakhrizadeh, as a key operator in Iran’s