On Saturday, the search was extended to include the area towards the Port of Aberdeen’s South Harbour and Duthie Park.
Officers are now carrying out fresh searches along the river, which still has floating ice patches on its surface following a week of plunging temperatures.
Relatives have urged people not to spread unfounded rumours about the sisters’ disappearance.
Detectives previously said there was nothing to suggest anything suspicious had happened to the women.
Officers made a fresh appeal for information on Saturday.
Ch Insp Darren Bruce said: “Eliza and Henrietta’s family are understandably extremely worried about them and we are working tirelessly to find them.
“We are seriously concerned about them and have significant resources dedicated to the inquiry.”
