It was the latest in a string of attacks targeting American interests after the 2003 US-led invasion of Iraq.
Iraqi militia groups fired two Katyusha rockets on a house in Baghdad, killing two women and three children and wounding two other children, the Iraqi military said on Monday.
Three Iraqi children and two women were from the same family and were killed when a rocket targeting Baghdad airport, where US troops are stationed, fell instead on their home, the army said.
The deaths were the first among Iraqi civilians in the latest outbreak of violence, during which Iran-backed Iraqi Shia militias have been blamed for targeting US interests in the country.
It was the latest in a string of attacks targeting American interests after Washington threatened to close its embassy and withdraw its 3,000 troops from the country unless rocket fire stops.
Attacks often target the US embassy in Baghdad, within the heavily fortified Green Zone, and US troops present in Iraqi bases as well as the Baghdad airport. Roadside bombs have also frequently targeted convoys carrying equipment destined for US-led coalition forces.
The frequency of the rocket fire has strained Iraq-US relations, prompting the Trump administration last week to threaten to close its diplomatic mission in Baghdad if Shia militia groups, believed to be behind it, are not reigned in.