WELLINGTON, Jan. 15 -- Eight of the 13 pilot whales stranded on a beach at the top of New Zealand's South Island on Tuesday were stranded again Wednesday after a brief period back in the sea.

Four of the 13 whales had died overnight, bringing the total deaths to five, said a statement from the Department of Conservation (DOC).

DOC rangers and volunteers would attempt to refloat the eight whales in the high tide at Farewell Spit on Wednesday morning.

Rescuers had refloated the whales late Tuesday, but were unable to fully get them grouped together and moving out to sea.

Another 50 or so whales in the pod had not been seen since DOC rangers in a boat lost sight of them in choppy seas on Tuesday.

DOC staff and volunteers spent all day Tuesday keeping the stranded whales cool with water and trying to shield them from the sun.

It is the second mass stranding on Farewell Spit this year after a pod of 39 long-finned pilot whales died after stranding themselves on Jan. 6.

DOC officers euthanized 27 whales after 12 died on the beach.