Mr. Holmes said that while recent military operations may have weakened the L.R.A., “they are still capable of wreaking absolute havoc — and they still do.”

He said he learned about the February attack on Saturday, when he met with local authorities and victims in Niangara, an old trading post hidden away in the Congolese jungle that has recently been ringed by roving bands of L.R.A. marauders.

One of the people he met was a young woman whose lips had been sliced off last month. She was attacked by rebels while working in her field, she said Saturday, sitting in a hospital bed, her face a mask of gauze and tape.

“They told me I was talking too much,” she said.

The L.R.A. has been waging a brutal and bizarre rebellion for more than 20 years, starting in northern Uganda in the late 1980s.

Originally, it said it was guided by the Ten Commandments, but soon it was breaking every one, massacring and mutilating civilians and becoming notorious for kidnapping young children and turning them into 4-foot-tall killing machines.