Colombian city _ deadliest place on earth _ undergoes change.(The Dallas Morning News)

BARRANCABERMEJA, Colombia _ A feeling that Mayor Julio Cesar Ardila defines as "tranquility" has settled over the Colombian riverport city that currently claims title, per capita, as the deadliest place on earth.

There are fewer bodies floating down the nearby Magdalena River these days, Ardila said. Not so many corpses are littering the streets when shopkeepers open their doors each the morning.

And out of respect for a new ambiance of enforced civility, teenaged militiamen say they are keeping their guns hidden while patrolling local neighborhoods. Unless, of course, they have specific orders to kill someone.

"We have gone five or eight days without a single murder," Col. Jose Miguel Villar, the regional National Police commander, said last week. He smiled with pride as he added, "What an honor!"

Barrancabermeja is a city of 300,000 inhabitants in the midst of transformation, due largely to the retreat three months ago of the nation's two largest guerrilla groups. Together, they had dominated life in Colombia's largest petroleum-refining center for nearly 20 uninterrupted years, Villar said.

Now there's a new authority imposing order on the streets. Villar asserted that the police and army troops, who patrol the streets each day in armored vehicles, are responsible for the new sense of tranquility.

Others beg to differ.