Washington ? Governors in states that accepted Katrina evacuees are being urged to locate about 2,000 registered sex offenders who fled the Gulf region during the hurricane’s mayhem and may have vanished from legally required tracking.

“When sex offenders know they’re being watched, when they know they’re being monitored, they are less likely to offend again,” said Wade Horn, assistant secretary for children and families at the Health and Human Services Department. “When they no longer believe they are being monitored or watched, they can be tempted to offend again.”

The Administration for Children and Families estimated that about 30 states are affected. In November, agency officials matched the names on sex offender registries in Louisiana, Mississippi and Alabama with the names of evacuees who applied for disaster assistance.

The agency came up with more than 2,000 matches. The find led Horn to work with the Federal Emergency Management Agency on a system that would allow state law enforcement agencies to find registered sex offenders who are receiving disaster assistance.

All states are required to have sex offender registries, and people convicted of sexually violent offenses are required to register their current addresses.

Horn wrote to the nation’s 50 governors in late November to alert them to the new search they could undertake with FEMA and the process they were to use.

States were not required to report back to the agency with their findings, so it’s unclear how many have acted on the federal government’s initiative. Some, however, had previously acted on their own.