Authorities in the Dominican Republic have resumed patrols to detain and deport migrants who lack documents after a more than yearlong hiatus.

The move comes weeks after the government ended a one-year period for migrants to apply for legal residency. Most of the migrants affected are Haitians.

The director of the government's immigrant detention center said only six Haitians had been detained as of Friday. Bernardo Jimenez said four of them were released after proving they had enrolled in the immigration program.

Authorities say nearly 289,000 people enrolled in the program out of an estimated 524,000 migrants living in the Dominican Republic. Migration officials say more than 66,000 people have moved to neighboring Haiti.

Haiti's government has warned that the actions by Dominican officials are creating a humanitarian crisis.