Rescue teams in South Africa were racing against time on Wednesday to find more survivors after a deadly building collapse in the country's Western Cape province, as search operations entered a third day.

Rescuers used underground cameras and sniffer dogs amid the rubble, looking for nearly 40 construction workers still missing, two days after the collapse of an apartment building under construction in the city of George.

At least eight people were killed as an under-construction five-story building collapsed on Monday for reasons that are still to be determined.

Hopes of finding survivors dwindle

At one point on Wednesday, rescuers were alerted to a "sound or tapping" coming from under the rubble, said George's mayor Leon Van Wyk.

But hopes are dwindling, as the chances of finding survivors are set to drop significantly, from the 72-hour mark after the building collapsed, the mayor said, with the clock ticking.

Operations would be entering the "body recovering" phase over the next day "as opposed to rescue," Van Wyk told national broadcaster SABC.

Twenty-nine of the 75 workers who were at the site when the collapse occurred have been pulled out of the rubble alive. Six, however, have life-threatening injuries, while 16 others are in a critical condition.

Investigations announced

Multiple authorities, including the police, the provincial government and the national department of labor, have announced probes into what caused the building to disintegrate.

"There will be consequences," said Anton Bredell, the Provincial Minister of Local Government, Environmental Affairs and Development Planning.

A city with a population of around 150,000 people on South Africa's picturesque coastal Garden Route, George is well known as a vacation and golfing destination.

jsi/kb (AFP, AP)