The killing of an Iranian nuclear scientist this week has provoked a wave of anger in Tehran, which blames Israel and the United States for the attack.
A hardline Iranian newspaper called on Thursday for retaliation against Israel, which Iranian authorities say orchestrated Wednesday's bomb blast. An editorial in the Kayhan newspaper called for assassinations of Israeli military and other officials.
The comments follow Tehran's call for the United Nations to condemn the attack and take steps toward eliminating what it called terrorism.
Both Israel and the United States have denied any role in the killing of the Iranian nuclear scientist.
The United States, other Western countries and Israel suspect Iran is using its nuclear program to build weapons. Iran says its nuclear ambitions are peaceful, and that the attack will not delay work on the program.
The scientist killed in the attack - Mostafa Ahmadi Roshan - supervised a department at the Natanz nuclear facility, Iran's main uranium enrichment site.
Iranian officials confirmed that a new underground complex has started refining uranium, and diplomats with ties to the U.N. nuclear agency say the work is being done at a much higher lever of purity.
Attackers have killed or wounded several Iranian nuclear scientists in recent years, including blasts in late 2010 that state media also attributed to bombs placed on cars by motorcyclists.
Iranian media said Wednesday two unidentified people on a motorcycle attached a magnetic bomb to Roshan's car. His driver was also killed.
Killing of Nuclear Scientist Fuels Anger in Tehran
![Undated photo released by Iranian Fars News Agency, claims to show Mostafa Ahmadi Roshan, who they say was killed in a bomb blast in Tehran, Iran, Jan. 11, 2012](https://gdb.voanews.com/c8c7da51-f5ff-418a-9c53-cd8496ced80d_w250_r1_s.jpg)