Russia believes Israel and the United States were responsible for unleashing the malicious Stuxnet computer worm on Iran's nuclear programme last year, a top official said Friday.

"We are seeing attempts of cyberspace being used by some states to act against others -- of it being used for political-military purposes," said the foreign ministry's emerging challenges and threats department chief Ilya Rogachyov.

"The only case in which experts believe the actions of states have been proven in this area ... is the Stuxnet system that was launched in 2010 against the centrifuge control system used to enrich uranium in Iran," he said.

"Experts believe that traces of this lead back to the actions of Israel and the United States," Rogachyov told reporters. "This is the only proven case of actual cyber-warfare."

Most of the Stuxnet infections have been discovered in Iran, giving rise to speculation it was intended to sabotage nuclear facilities there. The worm was crafted to recognize the system it was to attack.

Tehran has also blamed Israel and the United States for the killing of two of its nuclear scientists in November and January.

Russia picked up the construction of Iran's first nuclear power plant from Germany in the 1990s and the unit was hooked up to the power grid system for the first time this month.

Worried by the rapid rise of advanced technology, Moscow has spent several years pushing the United Nations into adopting new guiding principles for the Internet age that prohibit countries from engaging in so-called cyber-warfare.

"We are categorically against this opportunity being secured in some sort of international agreements," said the foreign ministry official.

"We believe that the international community must agree on certain principles of establishing national jurisdiction over cyberspace."

The United States has in turn only supported initiatives that help protect the physical safety of communications cable used by the Internet, Rogachyov said.