SANTO DOMINGO (Reuters) - The Dominican Republic deported five people of Haitian descent on Saturday under a controversial migration policy that set a deadline for undocumented foreigners to apply for temporary residence, according to local media.

Immigration Director General Rubén Paulino Sem confirmed the deportations at the Dajabón border post on Saturday morning, according to the Listín Diario newspaper.

Officials in the Dominican Republic have grown concerned by a long-running influx of people from neighboring Haiti and a 2013 Dominican court ruling that stripped citizenship from children born to undocumented immigrants, the vast majority of which are Haitian.

After an international outcry, the Dominican Congress passed a law allowing some migrants to apply for residency before a June 17 deadline. The government said last month that 289,000 people who had started the process can stay for up to two years.

At a press conference on Friday, Foreign Minister Andrés Navarro said the government was doing no more than enact its Migration Act after a temporary suspension of deportations to allow migrants to obtain proper documentation.

"What the government is doing is the regular enforcement of the immigration law," Navarro said. "Deadlines have passed ... and the regular enforcement has been resumed."

The Dominican Republic, which shares the Caribbean island of Hispaniola with its impoverished neighbor, has a population estimated to be as high as 1 million people originally from Haiti.

A U.S. State Department spokesman said the Obama administration was aware of the decision and urged the Dominican government "to avoid mass deportations."

Haitian officials have warned they lack the resources to handle mass deportations, but tens of thousands of Haitians and Haitian-Dominicans have already fled the Dominican Republic with many settling in squalid camps in Haiti.

Haitian officials recently estimated the population at four camps in the south of Haiti as at least 2,000 and growing.

At a detention center in the town of Haina, a few minutes from the capital of Santo Domingo, armed guards said half a dozen Haitians had been detained. More than a dozen prison-style buses with barred windows stood waiting to transport detainees.

The United States was concerned that some people with a right to citizenship or residency might be swept up in the deportation process due insufficient time and resources to obtain proper documentation, deputy State Department spokesman Mark Toner said in a statement on Friday evening.

"In all cases, the Dominican Republic should take measures adequate to prevent the risk of statelessness and the discriminatory confiscation of documents," Toner said.