WEDNESDAY, Nov. 14, 2018 (HealthDay News) -- Twenty percent of homicides of U.S. children ages 2 to 14 years are related to intimate partner violence, a new study indicates.

That's double the rate in the National Violent Death Reporting System, according to Harvard School of Public Health researchers.

For the study, the researchers analyzed data on nearly 1,400 children in 16 states who were homicide victims from 2005 to 2014.

The study was published online in the American Journal of Preventive Medicine and was presented Monday at the annual meeting of the American Public Health Association, in San Diego.

"We know that the burden of intimate partner violence extends beyond the partners involved. Our study documents that one in five child homicides are related to [domestic violence]," lead investigator Avanti Adhia said in an association news release.

"These crimes are often triggered by divorce or custody issues. Over 60 percent involved firearms and most incidents took place at home," said Adhia, currently a senior fellow at the University of Washington's Harborview Injury Prevention and Research Center, in Seattle.

Many of the gun-related homicides are committed by men, who then take their own lives, the study authors noted.

The mental harm to children who witness domestic violence has been well documented. But less attention has been paid to related physical harm to children, according to the report.

The researchers hope the findings add urgency to the need for resources focused on helping "people cope with stressors before they lead to deadly incidents, and limiting access to firearms," Adhia explained.

"We also hope to contribute to the improvement of [the National Violent Death Reporting System], a critical surveillance system that enables law enforcement, policy makers, and researchers to monitor violent deaths over time, across the country," she added.

More information

The U.S. Centers for Disease Control and Prevention has more on intimate partner violence.