* Suspect to stand trial in U.S. for drug trafficking
* Victims fear murders will remain unresolved
By Helen Popper
BOGOTA, March 5 (Reuters) - Colombia on Thursday extradited a former paramilitary chief to the United States on drugs charges, angering the families of militia victims who say hundreds of murders and kidnappings will now go unsolved.
Ever Veloza, who has admitted involvement in some 3,000 killings in the Andean country, boarded a U.S. Drug Enforcement Administration plane amid tight security, handcuffed and wearing a bullet-proof vest, local media said.
"He was handed over to DEA agents who took him by plane to the United States so he can face a federal court," a police spokesman said.
The extradition of Veloza, also known as "HH", came a day after another one of Colombia's most-wanted suspects with links to paramilitaries was flown to Miami to stand trial for cocaine trafficking and money laundering.
Colombia's conservative president, Alvaro Uribe, has been a loyal ally in U.S. efforts to fight drug trafficking in the world's No. 1 cocaine producer and has sent 700 suspects to face trial in the United States since taking office in 2002.
Some drug kingpins and former paramilitary leaders have continued to direct operations from their prison cells in Colombia and they fear extradition to the United States, making it one of Uribe's favored weapons in his security crackdown.
Colombia' Supreme Court authorized Veloza's extradition last year, but the government delayed it so he could take part in a process to confess more of his crimes in order to discover the whereabouts of missing bodies.
However, Thursday's extradition revived controversy about sending former paramilitary leaders to face trial on cocaine charges when rights crimes have not been resolved.
"When paramilitaries are extradited, the country and especially the families' victims lose out, they lose the truth and they lose justice," CRIC, an indigenous peoples' group based in the southern Cauca region, said in a statement.
Victims' relatives and human rights campaigners say the extradition of Veloza means the whereabouts of mass graves may never be found.
Veloza was a leader of the far-right United Self-Defense Forces of Colombia, or AUC, one of the paramilitary groups set up in the 1980s by wealthy Colombians to fight leftist rebels.
He took part in controversial peace negotiations between paramilitary commanders and Uribe which started in 2003, but he refused to turn himself in to face jail and went on the run. Police eventually captured him in 2007. (Additional reporting by Luis Jaime Acosta; editing by Mohammad Zargham)