TEHRAN, Iran (CNN) -- Iran has arrested suspects in connection with the July 2011 killing of a nuclear scientist, semiofficial media reported, citing Intelligence Minister Heidar Moslehi.

Moslehi made the announcement Sunday at an event marking the first anniversary of the death of 35-year-old physicist Daryoush Rezaie.

In addition to the suspected "terrorists" who shot and killed Rezaie outside his Tehran home on July 23, 2011, "two groups in charge of training terrorists were arrested inside and outside Iran," Moslehi said, according to the semiofficial Fars news agency. Moslehi did not provide details.

Rezaie taught at Mohaqeq Ardebili Technical College, in the northwestern city of Ardebil, according to the semiofficial Mehr news agency.

His death followed bombing attacks on two other Iranian physicists in November 2010, Iranian media said. Professor Majid Shahriari was killed, but professor Fereydoun Abbasi and his wife escaped with only minor wounds. Shahriari's wife and driver were injured. Both professors were on the faculty of Tehran's Shahid Beheshti University. Assailants on motorcycles attached bombs to cars carrying the professors at separate locations.

In January 2010, Iranian elementary-particle physicist Massoud Ali-Mohammadi was also killed in a bomb attack, according to Mehr. Ali-Mohammadi, 50, was riding his motorcycle near his Tehran home when a remote-controlled bomb planted on the bike detonated, according to Iranian media.

Majid Jamali Fashi was convicted in that killing and also found guilty of spying. Prosecutors accused him of working for the Mossad, Israel's national intelligence agency, and said Israel paid him $120,000 to carry out the hit. He was hanged in May.

Iran has blamed spy agencies in Israel, the United States and the United Kingdom for the attacks.

Israeli President Shimon Peres told CNN on Monday that Israel has never claimed responsibility for the attacks, but he said his country has a right to prevent the killing of its citizens.

CNN's Elise Labott contributed to this report.