A Japanese expert on Middle East affairs says that Israel's reported attack against Iran was carried out with restraint.

US media outlets have cited US government officials as saying that Israel attacked Iran. Israel had threatened to take retaliatory measures in response to Iran's large-scale missile and drone attack over the weekend.

Professor Tanaka Koichiro of Keio University said in an interview with NHK on Friday that the report came as no surprise to him because he had been assured that it would definitely take place.

The professor said Israel apparently intended to show off its capability to keep nuclear-related sites within its range by attacking the region that houses the facilities.

But he added that the attack was carried out on Friday morning, a day of rest when many businesses and government offices are closed, suggesting Israel's intention to minimize casualties.

As for possible responses from Iran, Tanaka said he believes Iran is trying to avoid being driven into a situation in which it has to stage a counteroffensive or an attack against Israel again. He feels Iran has concluded that there is no need to take a retaliatory action because interceptions have been made and there was no serious damage.

He said Iran seems to be acting in a way to avoid fighting with Israel or escalating the friction.

But the professor stressed the need to closely watch how things will unfold.

He said that if the two nations continue regularly attacking each other, it may develop into an unexpected scenario.