Teuku Nurmadi, a Maritime Affairs and Fisheries Ministry official in Aceh, meanwhile said it is rare for whales to strand in the area and that the animals may have become disorientated while migrating.
The whales beached at Ujong Kareung beach in Aceh province on Monday, attracting hundreds of onlookers who posed for selfies with the stranded mammals.
"Rescue effort is now underway with, among others, BPSPL Padang", the Jakarta-based marine mammal conservation organization wrote.
"Usually, sperm whales will avoid going into deep water if they're sick".
About seven whales were released before sunrise as rescuers worked through midnight and treated a pair of injured whales, Whale Stranding Indonesia told The New York Times. "So, we assume the leaders were sick and the others automatically followed the leaders to the beach", Prabowo said.
Dozens of volunteers waded on to the reef to rescue the stranded sperm whales, which are among the biggest mammals on earth, growing up to 12 meters and weighing up to 57 metric tons.
Also a year ago, eight pilot whales died after a mass stranding on the coast of Indonesia's main island of Java.