The 18.5-metre-long blue whale ran aground on Friday on Popoyo Beach, l45 kilometres southeast of Managua, according to the authorities.

About 300 people tried all afternoon and part of the night on Friday to save the whale but that proved impossible, Environment and Natural Resources Ministry delegate Mario Rodriguez said on government media.

The last hope was that high tide would carry the creature out to sea, but, he said, that never happened.

The Pacific region off Nicaragua's southern coast sees a lot of humpback whales and dolphins at this time of year.