Explosions rang out in the Iranian capital Teheran on Tuesday despite United States President Donald Trump saying Israel had called off airstrikes, at his command, to preserve an hours-old ceasefire.

Witnesses in Teheran said they heard two loud explosions, while Israeli army radio said its forces had struck a radar site near to the city. In addition, the Iranian Students' News Agency reported witnesses hearing explosions near the northern city of Babolsar, where air defenses have been triggered, according to broadcaster Al Jazeera.

Israeli Prime Minister Benjamin Netanyahu's office said Israel still carried out one more attack and "destroyed a radar installation near Teheran" after Trump's appeal, but is refraining from "further strikes".

The pair spoke by phone again after Trump declared a ceasefire was "in effect" earlier on Tuesday.

Trump, who was en route to a summit of the NATO military alliance in the Netherlands, said Israel had called off its attack, after rebuking the authorities in Jerusalem with an obscenity, in an extraordinary outburst aimed at an ally whose military campaign he had joined just two days earlier.

"All planes will turn around and head home, while doing a friendly 'Plane Wave' to Iran. Nobody will be hurt, the Ceasefire is in effect!" Trump wrote in a post on his Truth Social network.

That followed an earlier post in which he had said: "Israel. Do not drop those bombs. If you do it it is a major violation. Bring your pilots home, now!"

Before departing the White House to go to the NATO summit, Trump told reporters he was unhappy with both sides for violating the ceasefire, but particularly unhappy with Israel, which he said had "unloaded" shortly after agreeing the deal.

"I've got to get Israel to calm down now," Trump said. Iran and Israel had been fighting "so long and so hard," he added, "that they don't know what they're doing."

Israel's latest attacks on Iran are a "sign of defiance", says Sultan Barakat, professor of public policy at Hamad Bin Khalifa University in Qatar. Through Israel's continued military operations against Teheran, Netanyahu wants to show Trump and the world that it is "Israel first", Barakat told Al Jazeera.