Thousands of people are bracing for deportations in the Dominican Republic after failing to obtain legal residency as part of a government program to crack down on migrants.

At least a few of them were turned away at midnight Wednesday's deadline after standing in line for more than 24 hours to submit applications to establish their legal status.

Most of those affected are Haitians or of Haitian descent.

More than 260,000 people enrolled in the immigration registration program, but officials say only some 10,000 have provided the required documents.

An estimated 460,000 Haitian migrants live in the Dominican Republic, which shares the island of Hispaniola with Haiti.

Authorities on Thursday were expected to patrol main cities across the Dominican Republic to detain and deport people.