Monitors of South Sudan's peace deal say the government's use of helicopter gunships and bomb-dropping airplanes in the country's civil war puts the lives of "civilians at considerable risk."

The monitors' latest reports released Wednesday are a window into an August 2015 peace agreement that has failed to stop the fighting. Tens of thousands have died.

The reports say the government used the gunships and aircraft in offensives against rebels in the northern town of Nassir over a six-month period ending in July.

In addition, government forces are accused of "looting, harassment and sexual violence" in the southern town of Yei, which has seen ethnic targeting.

Diplomats are debating whether to scrap parts of the peace deal that they say have become tools for the country's leaders to retain power.