The evening attack was followed by a fresh rocket and drone barrage targeting the airport around midnight, a security source told AFP.

The Iraqi government's security media cell earlier confirmed that at 07:00 PM (1600 GMT) "five rockets targeted Baghdad International Airport and its surrounding area, injuring four airport employees and security personnel, and an engineer".

It added that rockets struck the airport and a water desalination plant and others crashed near a prison where Islamic State group (IS) suspects are detained as well as at an Iraqi airbase next to the US diplomatic facility.

A few hours later, initial official reports indicated rockets crashed inside the airport base housing the US diplomatic facility, the security source said.

Security forces had earlier seized the launchpad used for the first attack in the al-Radwaniya area southwest of Baghdad, the government media cell said.

Baghdad's airport includes a sprawling military complex that is divided into several bases belonging to the Iraqi army and security services, as well as a US diplomatic and logistics facility, and a central prison.

Since the start of the Middle East war, Iraq -- long a proxy battleground between the US and Iran -- has closed its airspace and suspended air traffic across the country.

Tehran-backed armed groups have claimed many of the daily drone and rocket attacks against US bases in Iraq, as well as Baghdad's airport.

Iraq's justice ministry warned earlier on Sunday that attacks near the airport threatened the security of the al-Karkh central prison housing thousands of IS suspects recently transferred from Syria.

The US embassy has also been targeted, with a drone striking the complex on Saturday. On the same day, three Iran-backed fighters were killed in strikes blamed on the US in the city.