The U.S. government's Pacific Northwest National Laboratory shut down Internet access to the facility after it suffered a cyber attack.
``PNNL is experiencing an Internet outage due to a cyber attack,'' the laboratory said in a voice mail message at the labs office of public affairs.
The voice mail of spokesman Greg Koller described it as ``a sophisticated'' cyber attack.
Officials with the laboratory, which conducts research on behalf of the U.S. Department of Energy, could not immediately be reached to elaborate on the recorded messages.
It comes in the wake of a cyber attack that shut down Internet access at the U.S. government's Oak Ridge National Laboratory in April.