The United States and Israel have launched strikes against Iran, with US President Donald Trump vowing to "annihilate" the country's navy and missile sites.

The Jurf al-Sakher base, also known as Jurf al-Nasr, in southern Iraq belongs to Hashed al-Shaabi or the Popular Mobilisation Forces (PMF), a former paramilitary group now integrated into the regular army.

But the base mostly hosts the powerful pro-Iran group Kataeb Hezbollah.

A source from Kataeb Hezbollah told AFP that "there are two martyrs from Kataeb and another five wounded in the aggression on the Jurf al-Nasr base."

The Iraqi government's security media cell announced that "at 11:50 am (0850 GMT), the Jurf al-Nasr area... was targeted by several airstrikes, resulting in the martyrdom of two people."

It also wounded three others.

The Hashed al-Shaabi confirmed the attack and the casualties.

A source in the Hashed al-Shaabi told AFP: "It is not clear yet if the attack was carried out by the Americans or the Israelis".

The US-blacklisted Kataeb has several brigades that operate within the Hashed al-Shaabi. It is also part of the Iran-backed so-called "axis of resistance" and has a reputation for acting on its own.

The group warned the US on Thursday of "immense losses" were it to start a war in the region, and it urged its fighters "to prepare for a potentially long war of attrition".