Twenty whales which were stranded onshore at the eastern Sri Lankan town of Sampoor have made it back to sea with the help of the navy and local residents, the navy said on Thursday.
Officials said they did not know why the whales had ended up on the beach near Trincomalee on Wednesday.
They were eventually helped back into the sea at high tide.
"It may be due to the change of the sea current or the increase of the sea surface temperature," navy spokesman Chaminda Walakuluge told Reuters.
The sea off Sri Lanka has been rough since last week because of a storm which later developed into Cyclone Mora. At least 206 people were killed and another 92 are still missing.
(Reporting by Ranga Sirilal; Writing by Shihar Aneez; Editing by Andrew Bolton)