The United Nations is urging Uganda to prosecute a captured field commander of the rebel Lord's Resistance Army.

Ugandan forces captured Caesar Acellam, one of the LRA's top military leaders, in the Central African Republic on Saturday. Since then, multiple Ugandan officials have said Acellam could receive a pardon under the country's Amnesty Act.

Radhika Coomaraswamy, the U.N. special envoy for children and armed conflict, said in a statement late Monday that she hopes “Ugandan authorities would not apply amnesty but instead, bring Acellam to justice.”

She said his prosecution would send a message to LRA leaders that they will be held accountable for their actions.

LRA chief Joseph Kony and other leaders of the group are wanted by the International Criminal Court for alleged war crimes and crimes against humanity.

The group has waged a 26-year reign of terror in Central Africa, attacking and looting villages, killing and abducting their inhabitants, and turning kidnap victims into child soldiers and sex slaves.

Uganda's amnesty law has allowed other LRA members to go free, even if they were accused of war crimes or crimes against humanity.

The LRA originated in northern Uganda in the late 1980s. Today, the group has no more than a few hundred fighters roaming around the Central African Republic, South Sudan, and the Democratic Republic of Congo.

About 100 U.S. military advisers are helping regional forces search for the LRA and Kony.