The US drive to expel illegal immigrants has separated more than 5,000 children from their parents, and another 15,000 face a similar fate in the coming years, a study said Wednesday.

The report by the activist Applied Research Center (ARC) found at least 5,100 children currently living in foster care because their parents have been detained or deported.

The report highlights the problems faced by children as the US government steps up efforts to expel undocumented immigrants.

ARC said government data showed the US deported 46,000 parents of children who are US citizens in the first six months of 2011. Government data for the fiscal year ended September 30 showed 397,000 expulsions, half of whom had criminal records.

"These deportations shatter families and endanger the children left behind," the report said.

"Immigration enforcement greatly increases the chances that families will never see each other again," said ARC president Rinku Sen.

"Detaining and deporting parents shatter families and endanger the children left behind. It's unacceptable, un-American, and a clear sign that we need to revisit our immigration policies."

The report indicates that children of deported immigrants represent 1.25 percent of the total in US foster care.

"Our research found time and again that families are being left out of decision-making when it comes to the care and custody of their children," said Seth Freed Wessler, author of the "Shattered Families" report.

"As a result, children of detained and deported parents are likely to remain in foster care when they could be with their own family."

Additionally, the report showed immigrant victims of domestic violence and other forms of gender-based violence are at particular risk of losing their children.

"When victims of violence are arrested, ICE (Immigration and Customs Enforcement)

too often detains them and their children enter foster care," the report said.

"Many immigrant victims face an impossible choice: remain with an abuser or risk detention and the loss of their children."

ARC describes itself as a think tank dedicated to racial justice.