Ambassador Peter Henry Barlerin made accusation in a state on the website of the US embassy in Cameroon after meeting President Paul Biya on Thursday.
"On the side of the government, there have been targeted killings, detentions without access to legal support, family, or the Red Cross, and burning of the separatists, and burning and looting of villages," he has discussed with Biya.
"On the side of the separatists, there have been murders of gendarmes, kidnapping of government officials, and burning of schools," he has added.
The US diplomat however appreciated the historic decision by Cameroon to investigate an alleged case of torture by government forces. He lauded Defence Minister Joseph BetiAssomo's recent communique about eventual punishment for military men who tortured a suspected separatist to death recent.
"We continue to call on both sides to stop the violence immediately. I asked the President to use his leadership to encourage both sides to listen to each other. One cannot have a dialogue until both sides are willing to listen to the others point of view," he pointed out.