Updated 3.45pm

The local telecoms providers are taking action to clamp down on spamming calls which might trick local subscribers into calling back and incurring huge costs.

According to Facebook, people reported that when they answer they hear silence and the call then disconnects – at which stage no damage has been done.

However, the problem starts if people try to call back, as these are international calls and very often linked to much higher call charges.

Vodafone has already blocked a series of telephone numbers in Switzerland, Tunisia and Albania after numerous people reporting receiving suspect phone calls from numbers they did not recognise.

People report that when they answer they hear silence and the call then disconnects – at which stage no damage has been done

A spokesperson for Vodafone said that the calls came from numbers starting with +41 7427850 (Switzerland) ****, +21 65850 **** (Tunisia) and +35 5450 **** (Albania).

The spokesperson said that Vodafone was investigating and originally warned that it might be that the number being called is only a front for a caller from much further afield, most likely in Africa, and that the calls could turn out to be very expensive. However, after further investigtion, this has now been ruled out.

“We cannot block incoming numbers – only a client can do that – but we can block outgoing numbers as we confirm them, which is what we are doing now,” she said.

GO said it had blocked the outgoing calls to the Switzerland some months ago, so no charges would be generated.

"If you did answer the call, no charges were applied. However, should any of GO customers roaming abroad call the Swiss number while roaming, they may be charged as they are not using GO’s network at that point in time," a spokesman warned.