Russia warned on Saturday that an "explosive escalation" in hostilities between Iran and Israel risked spiralling out of control, after Israel bombed military targets in the Islamic republic.

Israel warned Tehran would "pay a heavy price" if it responded to the retaliatory strikes, and the United States and Britain both demanded Iran not escalate the conflict further.

Russian foreign ministry spokeswoman Maria Zakharova said she was concerned about "the ongoing explosive escalation" in the region. "We urge all parties involved to exercise restraint, stop the violence and prevent events from developing into a catastrophic scenario," she said in a statement.

"It is necessary to stop provoking Iran into retaliatory actions and get out of the spiral of uncontrolled escalation," she added.

Russian President Vladimir Putin told a summit of the BRICS group of emerging nations this week that tensions between the two regional heavyweights risked leading to a full-scale war in the Middle East.

"The level of confrontation between Israel and Iran has sharply risen. This is all reminiscent of a chain reaction and puts the whole Middle East on the verge of full-scale war," the Russian leader said.

Moscow has close relations with Iran and has expressed concerns about a wider conflict in the region, where it has security and economic interests.