Householders in Mayo and Cork have been inundated with calls intended for Pakistan and Sudan, due to a technical problem at an international phone exchange.
One householder in Partry, Co Mayo, received 75 calls within 24 hours, as the Danish exchange diverted calls from Britain intended for Pakistan to the west of Ireland.
Further south, in Youghal, Co Cork, householders had the same problem as calls from Britain intended for Sudan were diverted there.
So many calls were flooding into the 092 Partry district, that worried householders alerted gardai and asked Eircom's Malicious Calls Unit to investigate.
Advice from the unit to use a caller identification device to trace the calls proved useless, as it flashed "caller unknown".
Finally, Eircom identified the root of the problem, a fault in the Danish phone network which meant that calls home from Pakistani expatriates resident in Britain were being routed to 092 (an area code for part of Mayo) instead of 0092, the international access code for Pakistan.
The area code for Youghal is 024, while the international access code for Sudan is 00249.
An Eircom spokesman said: "What happened in Mayo and Cork is quite unusual, but I would stress there was nothing Eircom could do about it."