Human rights groups are complaining that there is growing evidence of Saudi warplanes dropping cluster bombs, provided to them by the United States on targets in Yemen’s northwest.

A global ban on cluster munitions was signed in 2008, though neither the United States nor Saudi Arabia was a signatory to the ban. The US continues to export the bombs, which leave unexploded bomblets across a area, often for years, but the Pentagon insists they only sell to countries that promise not to use them on civilians.

Yet America’s own recent history with cluster bombs is checkered, at best, having littered civilian populated areas in Iraq and Afghanistan with such bombs, leaving the brightly colored bomblets to be found by children. The US has similarly shipped the bombs to both Israel and Saudi Arabia, nations which have been racking up major civilian death tolls in recent wars.

Saudi Arabia is denying the use of cluster munitions, though photographs coming out of Yemen show what appear to be CBU-105 US-manufactured cluster munitions, which the US has supplied to both Saudi Arabia and the United Arab Emirates in recent years.

The timing is particularly inopportune for the US, which has publicly backed the Saudi war but insists they are “concerned” about the growing civilian death toll. The Pentagon has also played a support role in the conflict.