Officials in a Croatian city are trying to find the young authors of a message in a bottle that washed up on an island.

Filip Bozic, 8, said he was playing on a beach on the island of Vis when he found a bottle that contained handwritten messages from sisters Matea and Mia, from Kastel Novi.

Matea's message, addressed to "pirates," said she was a third-grader and was preparing to launch the message into the Adriatic Sea.

Bozic found the message Saturday, 15 days after the date on Matea's note.

The City of Kastela shared the saga on its website, asking for more information on Matea and Mia, who did not include their last name or any contact information in the message.