Iran's intelligence minister says authorities have arrested more than 10 suspects in connection with last year's assassination of a nuclear scientist.
Heydar Moslehi alleged Tuesday the suspects are connected with Israel's Mossad spy agency, and warned that any nations providing support to Israel represented a threat to the region.
Nuclear physics professor Massoud Ali-Mohammadi was killed last year when a remote-controlled bomb exploded outside his home in northern Tehran.
On Monday, Iran blamed the United States and Israel for his death.
U.S. officials have called the accusation of involvement absurd. Israeli Cabinet Minister Benjamin Ben Eliezer said last year he knew nothing about the incident, but that it was not surprising Iran blamed Israel.
Iran says its nuclear program is for civilian purposes, while a number of governments believe Iran is working to develop nuclear weapons.
The United Nations Security Council has imposed four sets of sanctions on Iran for its refusal to stop enriching uranium.