A COLOMBIan thought to be one of the world's worst serial killers begged forgiveness when he confessed to murdering 140 children in a seven-year rampage.

Authorities have been forced to move Luis Alfredo Garavito for fear of his being lynched.

Garavito, a 42-year-old drifter and alcoholic who has been jailed on attempted rape charges since April, reportedly confessed after a five-hour interrogation on Friday in which he was presented with an overwhelming body of evidence against him.

The evidence included results of DNA testing on strands of hair found at some murder sites and a shoe and pair of spectacles found at two others, all of which were linked directly to Garavito.

Travel records, such as bus and hotel receipts, put Garavito at the scene of many murders. The nylon rope found in the home he shares with two women in the western city of Pereira was identical to that used to bind many victims, who were mostly male, from poor families, and aged eight to 16.

Prosecutor Alfonso Gomez has said many victims were plied with alcohol before being tortured and raped and having their throats slit. In some cases the victims were beheaded.

''I want to ask forgiveness for everything I've done, and I'm going to confess,'' Garavito blurted out after his interrogation, El Tiempo reported.

''I killed them, yes, and not just them, I killed others,'' he said, apparently referring to 25 children whose remains were found last year in a mass grave in Pereira.

At that point, a prosecution videotape showed, Garavito pulled a crumpled notebook from his pocket and showed how he had scrawled 140 lines through unintelligible symbols scribbled on the pages, his own secret way of tallying each of his victims' deaths.

Since his confession, Garavito - who had been held in the main prison in Villavicencio, just outside Bogota - was transferred to a special detention facility.

''We can't leave him in prison, he'd be lynched in no time,'' a judicial official said.

Garavito had also been placed under a round-the-clock suicide watch, given what the official called the strong possibility that he would try to take him own life.

El Espectador newspaper dubbed Garavito the ''Solitary Sadist''. Others quoted National Police chief General Rosso Jose Serrno as saying the child killer was a prime example of why Colombia, which does not have a death penalty, should move quickly to approve one.

The country has one of the world's highest murder rates and a 10-year guerrilla war has taken 35,000 lives.

The remains of 114 of Garavito's alleged victims have been unearthed from shallow graves. If he killed 140 children he would rank as history's second most prolific serial killer, just behind fellow Colombian Pedro Armando Lopez. Dubbed the ''Monster of the Andes,'' Lopez allegedly killed 300 young girls in Colombia, Peru and Ecuador and was jailed in 1980 on 57 counts of murder.

The Guinness Book of Records lists Colombian bandit leader Teofilo ''Sparks'' Rojas as the century's worst murderer. He was believed to have killed up to 3500 people between 1948 and 1963.

Garavito, who posed as a priest, a charity worker, a street vendor, and a cripple to lure his victims in more than 60 towns, was the eldest of seven brothers and sisters. He says he was physically and mentally abused by his father, who stopped him having relationships with girls while growing up in the town of Genova.

Garavito also said he had been raped on several occasions by two different men in Genova.-Reuters