A mini-tsunami has hit the Cape west coast without prior warning, SABC reported on Saturday.

Weather experts said unusual tidal patterns have been reported since Thursday and there has been some damage to buildings along the St Helena Bay coastline.

Disaster management teams have been placed on high alert.

Craig Lambinon of the National Sea Rescue Institute said their offices have been flooded with calls about unusual tidal activity.

Former Cape Town University oceanography professor, Geoff Brundrit, said there has been concern that there could be a repeat of the devastating tsunami that hit southeastern Asia in 2004, killing more than 300 000 people. He said South Africa may be affected in the near future.

Parts of Africa's east coast were affected during the 2004 Boxing Day tsunami, which killed thousands. At the time no tsunami warnings had been issued.

The Hawaiian monitoring centre did not pick up this mini-tsunami perhaps due to its low measurement on the Richter scale.

The South African Navy and the Council for Geosciences are investigating this phenomenon.

Sapa