A terrorist group named "Iran Royal Association" took responsibility for Tuesday's fatal bombing attack on an Iranian nuclear physicist, local Iran Daily reported Wednesday.

The Iran Royal Association, a group seeking to reestablish the Pahlavi reign in Iran, announced Tuesday in a statement that its " Tondar Commandos" were behind the assassination of Massoud Ali- Mohammadi, a particle physics professor in Tehran University, according to the report.

The website of the group said it had previously threatened Ali- Mohammadi with death.

The Iran Royal Association, headed by Foroud Fouladvand, was also responsible for a deadly bombing in the tourist city of Shiraz in April 2008, during which 13 people were killed and hundreds wounded.

Ali-Mohammadi was killed Tuesday morning when a bomb strapped to a parked motorcycle was triggered by remote control outside his home in the Qeytariyeh neighborhood.

Police sealed off the area and launched an investigation.

Iran's Foreign Ministry responded to the attack by saying that there were traces of U.S. and Israeli involvement in it, according to the state IRIB TV.