MILAN (AP) — Migrants picked up at sea by a mercantile ship and brought to Italy by the coast guard have reported that six people died of thirst during the voyage, the U.N. refugee agency said Monday.

The Italian Coast Guard said it transported 26 migrants to the Sicilian port of Pozzallo who were among 28 people, mostly Syrians and Afghans, rescued in recent days from a small boat in distress off the coast of Libya by a mercantile ship flying the Liberian flag. A child with dehydration and his mother were transported to the Maltese capital of Valletta by helicopter from ship.

The migrants arriving in Italy told officials from the U.N. High Commissioner for Refugees that six people, including a small child and a 12-year-old, had died of dehydration while on board the ship and that their bodies had been left at sea. The victims appeared to have all been Syrians.

So far this year, more than 1,200 people have died or are missing at sea in the perilous central Mediterranean crossing from North Africa to Europe. The U.N. refugee agency said the route the small boat had taken and how many days it had been at sea was not clear.

Follow all AP stories on global migration at https://apnews.com/hub/migration.