Footprints thought to be from the critically endangered Sumatran rhino have been found in Indonesia, a conservation group says.
The team from WWF-Indonesia made the discovery in February while monitoring orangutans in West Kutai, East Kalimantan province, on Borneo island.
A follow-up survey showed more rhino tracks and signs of activity.
There has yet to be a visual sighting of the rhinos and their numbers remain unclear, the group says.
It is estimated that fewer than 200 Sumatran rhinos, the smallest in its species, exist in Indonesia and Malaysia.
They were believed to be extinct in Kalimantan from the 1990s, a statement from WWF-Indonesia says.
The group worked with government forestry officials and scientists at the University of Mulawarman to verify initial findings.
"We got some strong indications [of rhino presence] in the forms of mud pond and scratches from horns on the bushes and trees," Yuyun Kurniawan, head of the WWF survey team in Borneo, told BBC Indonesian.
The survey team was also able to identify more than 20 plant species that rhinos feed on in the area.
The location of the footprints has not been revealed because of fears of poaching.