At least three people were injured after five explosions hit a military base belonging to an Iran-backed militia in Iraq, media reports said.

The blasts happened at a site belonging to the Popular Mobilization Units (PMU), according to Muhannad al-Anazi, a member of the Security Committee in Babylon Governorate, south of the capital Baghdad, reported CNN.

Israeli and US officials have so far not commented on the involvement in the explosions.

The explosions occurred just a day after Israel had carried out a strike inside Iran.

Israel has carried out a military strike inside Iran, a US official earlier told CNN Friday, a potentially dangerous escalation in a fast widening Middle East conflict that Iranian government officials have so far sought to play down.

Iran’s air defense systems were activated in the cities of Isfahan and Tabriz after three explosions were heard close to a major military airbase near Isfahan, the American news channel reported on Friday.

Meanwhile, Iranian President Ebrahim Raisi made no mention of Israel's Friday (local time) strike on Iran, while publicly lauding the unprecedented Iranian military operation last weekend targeting the "Israeli-occupied territories", reported CNN.

The US authorities posted on X that the country did not conduct any airstrike on Iraq on Saturday.

"We are aware of reports claiming that the United States conducted airstrikes in Iraq today. Those reports are not true. The United States has not conducted air strikes in Iraq today," US Centcom posted on X.

Antonio Guterres reacts

Following reports of alleged Israeli strikes inside Iran near a nuclear power station early Friday, the UN Secretary-General António Guterres issued a new appeal to all parties to “stop the dangerous cycle of retaliation in the Middle East”.

“The Secretary-General condemns any act of retaliation and appeals to the international community to work together to prevent any further development that could lead to devastating consequences for the entire region and beyond,” he said in a statement issued by his office.

Echoing those concerns, UN atomic energy agency chief Rafael Grossi urged “extreme restraint” from all sides, after more than six and a half months of war in Gaza that have fuelled fears of a wider regional conflict.

“IAEA can confirm that there is no damage to Iran’s nuclear sites" and Director-General Grossi "continues to call for extreme restraint from everybody and reiterates that nuclear facilities should never be a target in military conflicts", the International Atomic Energy Agency said in a tweet following unconfirmed media reports that possible drone strikes had targeted the Iranian province of Isfahan, which is home to nuclear facilities and military garrisons.

In Geneva, too, the UN human rights office, OHCHR, urged all parties “to take steps to de-escalate the situation” rapidly.

“(We) call on third States, in particular those with influence, to do all in their power to ensure there is no further deterioration in an already extremely precarious situation,” said OHCHR spokesperson Jeremy Laurence.