House and Senate officials suspended mail delivery Friday in the wake of reports from the U.S. Postal Service of possible anthrax contamination at a Washington, D.C. mail processing facility.

USPS officials announced late Thursday that initial air samples taken at the Naval Consolidated Mail Facility in Anacostia tested positive for anthrax, and that additional tests would be conducted.

In the meantime, USPS officials closed 11 locations that supply mail to the Anacostia branch, including the V Street Northeast facility, which distributes mail to the House and Senate as well as a number of other government agencies.

“The House, as a precaution, will hold all mail and package deliveries until the Naval and Postal Service V Street facility situations have been clarified. For Friday morning, November 7, a delivery of Dear Colleagues and periodicals will occur,” states an e-mail issued this morning by the office of the House Chief Administrative Officer.

The Senate Sergeant-at-Arms issued a similar e-mail notification, stating that internal mail would continue to be delivered along with items from the Congressional Acceptance Site, which screens hand-delivered packages.

“Staff are reminded to only accept envelopes and packages from uniformed Senate Post Office employees or government couriers bearing a current picture ID,” the Senate e-mail states.

It was not immediately clear when mail service will resume on Capitol Hill; however, one Congressional aide said the decision to suspend delivery in the House was primarily a precaution.

“The equipment used in the initial site testing has had a history of some false positives, we’re obviously monitoring it … but the House mail takes a very different route,” the aide said.

Mail sent via the U.S. Postal Service to Congress, the Supreme Court, the White House and federal agencies has been irradiated following the arrival of anthrax-tainted letters on Capitol Hill in October 2001.

The Sergeant-at-Arms e-mail also states: “Senate staff are reminded that all Senate USPS mail is irradiated and both Senate and House USPS mail and national shipper packages (UPS, FedEx, etc.) go through additional testing and quarantine before delivery to Senate offices. To date, testing has been negative, showing no contamination.”