- [Narrator] The assassination took place

just outside of Tehran.

An Iranian journalistciting regime officials

said the ambush began with a car bomb,

and then a 12-member squadopened fire on the three cars

with the nuclear scientistand his bodyguards.

But one top Iranianofficial accused Israel

of using remote electronic devices

to carry out the assassination.

While no one has claimed responsibility

for the attack, Iran'sForeign Ministry Javad Zarif

blamed Israel, andIran's President Rouhani

pledged retaliation.

- [Man] At the right time,the relevant officials

will respond to this crime.

- [Narrator] An Iraniannewspaper suggested Iran attack

the Israeli port city of Haifa in order

to inflict heavy casualties.

On Sunday, the IDF Chief of Staff,

Lieutenant General Aviv Kochavi

visited Israel's northern border,

and said, "Our message is clear.

We will remain fully preparedagainst any manifestation

of aggression against us."

Prime Minister Netanyahuspecifically mentioned

the chief scientist afterrevealing how Mossad

covertly stole Iranian's atomic secrets.

- This is how Dr. Mohsen Fakhrizadeh,

head of Project Amad put it.

Remember that name, Fakhrizadeh.

- [Narrator] Amos Yadlin,

former Chief of Israel'smilitary intelligence says Iran

has twin tracks toward a nuclear bomb,

the public side where they enrich uranium

under watch by the UN.

And a secret military programheaded by Fakhrizadeh.

- The damage to the covert,weaponization program,

is huge.

No doubt that he was thecore source of authority,

knowledge and organizationof this program.

- [Narrator] Yadlin, sees two main options

for Iranian leaders.

Wait for a potential Bidenadministration or retaliate now.

- 'Cause they can use their proxies,

Hezbollah, the Houthis in Yemen,

or their Shia militia in Syria or Iraq.

And they can go to an extreme step

which is launching missiles from Iran.

- [Narrator] Biden supportersof the former Vice President

blasted the assassination.

Former Obama CIA DirectorJohn Brennan tweeted,

"This was a criminalact and highly reckless.

It risks lethalretaliation and a new round

of regional conflict.

Iranian leaders would be wise

to wait for the return ofresponsible American leadership

on the global stage, and to resist

the urge to respond againstany perceived culprits.

For now, the region is waiting

and watching for any response,

and if it puts the MiddleEast on the brink of war.

Chris Mitchell, CBN news, Jerusalem.