A temporary fault has left thousands of telephones in Guernsey unavailable.
Network operator Cable & Wireless said it believed a power fault caused the problem to the island's telephones on Monday afternoon.
The fault has affected numbers beginning with the digits seven, two-zero and two-four.
A Cable & Wireless spokesman said engineers were looking into the problem and it was still unclear when connections would be restored.
Emergency calls are being diverted through Jersey's telephone system.