Human rights groups are welcoming the U.S. decision to deploy 100 U.S. troops to central Africa to support the regional fight against a guerrilla group known for atrocities against civilians.

One of those groups, Human Rights Watch, has been urging the Obama administration to increase efforts to protect people from the Ugandan Lord's Resistance Army.

The rebel group, led by Joseph Kony, has been accused of kidnapping children, murder and rape in Uganda and neighboring countries.

On Friday, U.S. President Barack Obama told Congress in a letter he has authorized a contingent of U.S. combat forces to help remove Kony from the battlefield. He said the U.S. soldiers will not engage the rebels directly, except in self-defense.

The first of the 100 U.S. troops arrived in Uganda Wednesday.

The U.S. troops are to provide information, advice and assistance in Uganda, South Sudan, the Central African Republic and the Democratic Republic of Congo.

The Lord's Resistance Army is accused of killing, kidnapping and mutilating tens of thousands of people across central Africa during a campaign that began in the late 1980s. Kony is wanted by the International Criminal Court for war crimes and crimes against humanity.

In his letter, Mr. Obama said that since 2008, the U.S. has been supporting regional military efforts to pursue the LRA and to protect local communities, but efforts to remove Kony and his top commanders have failed.

Mr. Obama also noted that Congress showed its support for U.S. efforts against the LRA by approving a 2010 law on the issue .