China urged Iran and Israel to "immediately" take steps to reduce tensions on Monday after Israel struck targets inside Iran and Tehran unleashed a barrage of missile strikes on Israeli cities.

"We urge all parties to immediately take measures to cool down the tensions, prevent the region from falling into greater turmoil, and create conditions for returning to the right track of resolving issues through dialogue and negotiations," Foreign Ministry spokesman Guo Jiakun said.

Israel's surprise assault on Iran last week, launched after decades of enmity and a prolonged shadow war fought through proxies and covert operations, has touched off the most intense fighting yet and triggered fears of a lengthy conflict that could engulf the Middle East.

Foreign Minister Wang Yi held phone calls with his Israeli and Iranian counterparts on Saturday and called on both countries to de-escalate tensions.

Guo said on Monday "all relevant parties should immediately take steps to put the brakes on the escalation and to cool down the tensions".

"Force cannot bring lasting peace," he said.

"China will continue to maintain communication with the relevant parties, and promote peace and encourage dialogue, to prevent further turbulence in the region." (AFP)