A rocket landed near an Iraqi military base hosting US forces in the northern city of Mosul late on Tuesday, an Iraqi military statement said, the second such incident in two days, Reuters reports.
The statement gave no immediate reports of casualties. It said the rocket fired was a short-range Katyusha missile.
Mosul's military commander said the rocket landed in an open space causing no casualties or damage. He said it was fired from west Mosul, across the Tigris river, and was a "locally made" rocket, without elaborating.
Security sources separately told Reuters that two Katyusha rockets had landed on the base.
On Monday, three rockets hit a base that hosts US forces north of Baghdad. The incidents coincide with tension ramping up between the United States and Iran, with Iraq seen as a possible site for any violent flare-up between the two sides.
There was no immediate claim of responsibility for the rocket fire near Iraqi bases this week.
The United States has blamed Iran for attacks on oil tankers in the Gulf and evacuated hundreds of staff from the US embassy in Baghdad last month as US officials cited unspecified threats from Iran-backed Iraqi Shi'ite militias against US interests.