The attack was the first time Western military or diplomatic installations have been targeted in Iraq in nearly two months, after a string of such incidents.

Under former US President Donald Trump, Washington had vowed that the killing of an American national in such a rocket attack would prompt a mass bombing campaign in Iraq.

At around 9:30 pm (1830 GMT), an AFP reporter heard several loud explosions in the northwestern outskirts of Arbil, the capital of Iraq's autonomous Kurdistan region.

Iraqi and Western security sources told AFP that at least three rockets were fired in the direction of the city's airport, where foreign troops are based as part of an international alliance fighting the Islamic State group.

Coalition spokesman Colonel Wayne Marotto confirmed to AFP that the dead contractor was not Iraqi, but could not give immediate details on the victim's nationality.

Two other rockets hit residential neighbourhoods on Arbil's outskirts.

Delovan Jalal, the head of Arbil's health directorate, told AFP at least five civilians were wounded and one was in critical condition.

In a statement, the Kurdistan region's interior ministry confirmed "several rockets" had hit the city and said security agencies had launched a "detailed investigation", urging civilians to stay home until further notice.

Following the attack, security forces deployed around the airport and helicopters could be heard on the city's edges, an AFP correspondent said.

There was no immediate claim of responsibility, although some pro-Iran propaganda channels were the first to report on the attack.

- Ceasefire violations -

Western military and diplomatic sites have been targeted by dozens of rockets and roadside bombs since late 2019.

The vast majority have hit the Iraqi capital Baghdad, although Iranian forces fired missiles at the Arbil airport in January 2020, a few days after Washington assassinated key general Qasem Soleimani at Baghdad airport.

Since then, volleys of rockets have regularly hit the US embassy in Baghdad, with both American and Iraqi officials blaming hardline pro-Iran factions including Kataeb Hezbollah and Asaib Ahl al-Haq.

These groups are vehemently opposed to the US-led coalition, which has been based in Iraq since 2014 to help local forces beat back the Islamic State group.

Since Iraq declared victory against IS in late 2017, the coalition has drawn down to under 3,500 troops in total, 2,500 of them Americans.

Most are concentrated at the military complex at the Arbil airport, a coalition source told AFP.

But even as the coalition withdrew more forces, rocket attacks continued, to Washington's growing frustration.

In October, the US threatened to close its embassy in Baghdad unless the attacks stopped.

The Iraqi government facilitated an indefinite truce with hardline groups and rocket attacks have come to a near halt.

But there have been violations, the most recent of which had been a spray of rockets targeting the US embassy on December 20.

- Tensions with Turkey -

The latest attack came amid rising tensions in north Iraq, where neighbouring Turkey has been waging a fierce land and air assault against the Kurdistan Workers' Party (PKK).

The PKK has fought an insurgency against the Turkish state since 1984, using the rugged mountains of neighbouring northern Iraq as a rear base.

Frustrated by the continued attacks, Turkey launched a major operation against the PKK in June 2020, using UAVs, air strikes and ground forces to clear out border areas.

There has been little comment from the Kurdish government in Iraq's north or authorities in Baghdad.

But in recent days, pro-Iran armed factions have made their toughest public comments yet on the incursions.

Asaib Ahl al-Haq said that if Turkey expanded its military operations into the strategic northwestern enclave of Sinjar, it would fight back, ostensibly to defend Iraqi sovereignty.

Another pro-Iran faction, Ashab Ahl al-Kahf, claimed on Monday it had attacked a Turkish military base along the Iraqi border.

Ashab Ahl al-Kahf is thought by Iraqi and Western officials to be a "smokescreen" for other groups, and AFP could not independently verify claims of a rocket attack on the border.