VANESSA ARRINGTON
  Associated Press

  BOGOTA, Colombia -A commander from Colombia's largest rebel group surrendered and, flanked by the country's president and top generals Monday,
  urged his former comrades-in-arms to do the same.

  Rafael Rojas, who said he was a 20-year veteran of the Revolutionary Armed Forces of Colombia and the commander of the group's 46th Front, was the
  highest-ranking member of the rebel army to turn himself in, authorities said. His surrender Friday was reportedly mediated by a Roman Catholic priest.

  President Alvaro Uribe on Monday introduced Rojas at a nationally televised news conference at a military base in the coastal city of Cartagena.

  Rojas urged other members of the 16,000-strong FARC - as the rebel group is known - to also surrender, saying the 38-year war has brought only ruin to
  this South American country.

  "Positive things have not resulted," said Rojas, wearing a blue denim shirt and blue jeans. "On the contrary, the prolonged war has left only desolation and
  destruction."

  Rebels who desert the FARC and other guerrilla armies are put up in protected housing and given the opportunity to change their identities. They also have
  access to health care, education and work training under the government program.

  "Take advantage of this as an opportunity for dialogue and to create a new society for coming generations," Rojas said.

  Uribe, a hard-liner who has stepped up the war against the rebels in his seven months in office, said other rebels should also surrender or face defeat.

  "The decision is to finish with the terrorist problem," Uribe said.

  The 46th Front operates in the northern state of Santander. The defense ministry estimated that about 250 men belong to the front.

  Nearly 400 rebels from the FARC and a smaller leftist rebel group, the National Liberation Army, have turned themselves in this year, according to the
  defense ministry.

  The FARC has said it is open to peace talks to end the war, but only if the government grants the rebel group a demilitarized zone - a request Uribe has
  refused. The guerrillas have also offered to release political hostages - including dozens of police officers, soldiers and politicians as well as three U.S.
  military contractors - in exchange for FARC rebels in prison.

  Some 3,500 people are killed every year in the fighting between rebels, illegal right-wing militias and the government and every day last year more than
  1,000 were forced to flee their homes, according to a Colombian human rights organization.