Israel and Iran have launched fresh waves of attacks as the war launched by the US and Israel nears its fifth week.
Israel said on Friday it had conducted "wide-scale" airstrikes in Tehran, while Iran's Revolutionary Guards carried out missile and drone attacks in the Gulf the previous day.
The Israeli military said it had hit missile launchers and storage sites near Iran's capital after Prime Minister Benjamin Netanyahu ordered an intensified bombing campaign in response to Donald Trump's renewed push for a ceasefire .
In the Gulf, US military sites in the UAE, Qatar, Kuwait and Bahrain came under Iranian fire.
The Iranian Revolutionary Guards warned of further attacks in the coming hours and urged civilians to stay away from US forces - including against hotels, which Tehran claims are hosting troops.
"The cowardly American-Zionist forces… are attempting to use civilian locations and innocent people as human shields," it said in a statement.
"We recommend that you urgently leave locations where American forces are stationed so that no harm comes to you."
Tehran has sent "firm warnings" to hotels in the region, particularly in the UAE and Bahrain, Iranian media quoted anonymous officials as saying.
The fresh strikes came hours after Trump delayed his deadline for Iran to reopen the Strait of Hormuz by another 10 days amid what he claims are ongoing negotiations with Iran to end the war.
The US president had last Friday vowed to destroy Iran's electricity grid before walking back his threat and alleging that Tehran is pushing for a ceasefire. A US-drafted truce proposal was rejected by Iran, which denied Trump's claims about negotiations. It has submitted its own set of demands for ending the war, including retaining control over the Strait of Hormuz and the payment of reparations for its wartime losses.
Amid speculation about a potential ceasefire deal, the US is continuing its buildup of ground forces , raising the prospect of further escalations in the coming days.
Thousands of US Marines are expected to arrive in the region on Friday, joining the 50,000 troops already in place.
US officials are considering sending up to 10,000 additional troops, The Wall Street Journal reported Friday.
The Trump administration is thought to have drawn up plans to seize Iranian territory in a bid to end the disruption in the Strait of Hormuz. Possible targets include the oil export hub of Kharg Island, islands at the mouth of the strait, and Iran's coastline.
Iran says it is mobilising one million people to fight off a potential invasion.