MIAMI (AP) - Some survivors of Haiti's earthquake have been detained by U.S. immigration officials for weeks because they lacked proper visas when they arrived.

Attorneys at the Florida Immigrant Advocacy Center say federal immigration officials held 30 Haitians at a detention center in South Florida even though they had no criminal histories and they were severely traumatized by the Jan. 12 earthquake.

Their documentation appears to have been overlooked in the frenzy to evacuate thousands of people from the crippled airport in Haiti's capital.

The attorneys have asked Immigration and Customs Enforcement to release the survivors. At least one would be released Thursday, according to a relative who said he was notified by immigration officials.