The source of the rocket is unknown, the sources said. It caused no casualties. Dujail is 50 km (30 miles) north of Baghdad. Balad base is about 80 kilometres (50 miles) north of Baghdad.
This comes amid an escalation of tensions between the US and Iran after Donal Trump authorised the targeted killing last week of Iran's top general, Qassem Soleimani. Iran responded overnight with its most direct assault on America since the 1979 seizure of the US Embassy in Tehran, firing more than a dozen missiles at two installations in Iraq. The Pentagon said Wednesday that it believed Iran fired with the intent to kill.
The US and Iran, however, stepped back from the brink of possible war as President Donald Trump signalled he would not retaliate militarily for Iran's missile strikes on Iraqi bases housing US troops.