"We believe they are the missing Japanese divers and they are alive," local police chief Nyoman Suarsika told AFP.
He said rescuers were on the way to the area close to Manta Point, off Nusa Penida island, which lies next to Nusa Lembongan.
"We have not been able to reach them yet," he added.
Rescue agency officials said earlier that a helicopter and two boats had been dispatched to the area to search for the remaining divers.
The five women who have been rescued are all in hospital in Bali. They have suffered dehydration and sunburn but none are in serious condition, doctors said.
"We caused many people so much worry over this case," one of the divers, Saori Furukawa, wrote in a note handed to Japanese media from her hospital bed. "I would like to take a rest for a while, hoping the remaining two are alive."
Kazuo Shibata, consul general at the Japanese consulate in Bali, told Japanese media he had visited four of the divers and that they were fine.
"They were moved to tears when I told them, 'It's so good you were rescued'," he said.