US Homeland Security employees locked out of computer networks: sources

U.S. Department of Homeland Security emblem is pictured at the National Cybersecurity & Communications Integration Center (NCCIC) located just outside Washington in Arlington, Virginia September 24, 2010. REUTERS/Hyungwon Kang

WASHINGTON: Some US Department of Homeland Security employees in the Washington area and Philadelphia were unable to access some agency computer networks on Feb 21, according to three sources familiar with the matter.

It was not clear how widespread the issue was or how significantly it affected daily functions at DHS, a large government agency whose responsibilities include immigration services, border security and cyber defence.