WASHINGTON - Two members of Pennsylvania's delegation of federal lawmakers are calling on the U.S. Immigration and Customs Enforcement (ICE) agency to provide them with more information about the Berks County Residential Center.

U.S. Sen. Bob Casey and U.S. Rep. Chrissy Houlahan, both Democrats, on Thursday released a letter that they sent to Matthew Albence, the acting director of the agency, which is part of the Department of Homeland Security.

The letter, the lawmakers said, follows a visit to the center in Bern Township amid reports they received of migrant families being denied access to medical care, mental health services, adequate sleep, and information about the length of their detention.

The letter also seeks information about the length of time families are detained, and clarity on the medical, mental health and other services provided to families.

"We have heard troubling accounts of medical care not being provided until children are very ill," the lawmakers wrote in their letter. "We have also heard that when residents are sent to the hospital or outside medical services and provided a prescription, those prescriptions will not be filled automatically. Rather, ICE providers will review and determine whether to provide the treatment."

Casey and Houlahan said they have also received reports of families being separated when a parent or child is sent to outside medical services.

Casey has been an outspoken opponent of the center since the days of the Obama administration.

The Berks County-owned center, which has been in operation since 2001 under a contract with the federal government, houses undocumented immigrant families while they go through the process of seeking asylum from their country of origin.

The center was again thrust into the national spotlight last week when seven members of a family from the United Kingdom, including three small children, decried the treatment they had received while being detailed there.

ICE representatives disputed their claims.

"BFRC provides a safe and humane environment for families as they go through the immigration process," ICE officials said in a statement. "Reports of abuse or inhumane conditions at BFRC are unequivocally false."

The family members unlawfully drove across the border from Canada to the United States in early October, officials said. They have since been deported.