The attack came just hours before Iran's new president, Masoud Pezeshkian, flew in for a three-day visit, his first foreign trip since taking office in July.

"There was an attack at the Baghdad Diplomatic Services Compound, a US diplomatic facility," the embassy said in a statement. "Fortunately, there are no reported casualties, and we are assessing the damage and its cause."

Iraq's Joint Operations Command had earlier reported an explosion inside an area of the airport occupied by international coalition advisers.

"Iraqi security forces were unable... to determine the origin of the explosion, which has not been claimed," the command's spokesman, Major General Tahseen Al Khafaji, said in a statement.

A senior military official, speaking on condition of anonymity, told AFP that "two Katyusha-type rockets" had caused the explosion.

"One fell on the wall of the Iraqi anti-terrorist forces compound. The second was inside the base hosting the international anti-jihadist coalition led by Washington."

US military and civilian facilities in Iraq have come under repeated attack, both by Sunni Muslim extremists and by Shiite armed groups backed by Iran.

The Baghdad airport diplomatic compound was previously targeted in January 2022.

Bases used by US troops came under a barrage of rocket and drone attacks by Iran-backed elements of Iraq's armed forces last winter, triggering retaliatory US air strikes in both Iraq and neighbouring Syria.

The Iraqi government responded by opening talks with the US administration on the withdrawal of the remaining US-led troops deployed against the Islamic State jihadist group.