Fresh strikes rocked Iran and Lebanon Friday as Israel and the United States stepped up their attacks in the sprawling Middle East war, with powerful explosions shattering the skies of Tehran.

An Israeli strike on an office building in the southern city of Sidon killed five people and wounded seven, the Lebanese health ministry said Friday, as Israel presses attacks on Lebanon's south, east, and in Beirut's southern suburbs.

The strike targeted the tenth floor of an office building near two shelters for displaced people and a Lebanese Red Cross center, an AFP photographer said.

Fresh Israeli strikes on Friday battered Lebanon, where Prime Minister Nawaf Salam warned "a humanitarian disaster is looming" due to mass displacement.

An Israeli strike on an office building in the southern city of Sidon killed five people and wounded seven, the Lebanese health ministry said, as Israel presses attacks on Lebanon's south, east, and in Beirut's southern suburbs.

The Israeli military on Friday said it had started a new "wave of strikes" on the southern suburbs of Beirut, a day after it ordered the evacuation of the area, home to hundreds of thousands of people, before launching a series of raids.

"The IDF is now striking Hezbollah infrastructure in the Dahieh area in Beirut," the military said.

Israel launched overnight into Friday air strikes on several towns in southern Lebanon.

"Enemy warplanes launched nighttime strikes on the towns of Srifa, Aita al-Shaab, Touline, Sawana and Majdal Selm," the National News Agency reported.

Israel's military chief said Thursday he had ordered troops to expand the area under Israeli control in southern Lebanon, as the country's ongoing operation against Hezbollah intensified.

French President Emmanuel Macron said Thursday "everything" must be done to prevent Lebanon "from once again being drawn into war", urging both Israel and Hezbollah to halt military operations.

U.S. President Donald Trump on Thursday insisted he should have a role in picking Iran’s next supreme leader after the killing of Ayatollah Ali Khamenei, whose son he said he found unacceptable.

The Lebanese health ministry said on Thursday that the death toll from Israeli strikes on Lebanon has risen to 102 since the country was drawn into regional war earlier this week.

The ministry added that 638 people have also been wounded since Monday, adding that the tolls were likely to increase as hospitals receive more victims.

Israel's far-right Finance Minister Bezalel Smotrich warned Thursday that a southern Beirut suburb, a stronghold of Hezbollah, will face devastation similar to Gaza after the Israeli military told residents to evacuate.