A Colombian paramilitary leader gave testimony Tuesday to a special tribunal about his group's role in massacres and assassinations.

Salvatore Mancuso (r) having his handcuffs removed in Medellin court

Salvatore Mancuso and other leaders of the United Self-Defense Forces of Colombia have agreed to speak to the court as part of a peace deal with the government.

Under the deal, the paramilitary leaders will serve limited prison sentences and receive protection from extradition to the United States for drug charges. Some 30,000 fighters also have laid down their weapons.

Several relatives of victims of paramilitary killings appeared at the tribunal in Medellin today to hear Mancuso's testimony.

Human rights groups have condemned the peace deal signed by the government, saying it is too lenient on paramilitary members.

Leftist rebels in Colombia have rejected peace talks with the government.