Hundreds of dead fish were found at Lake Koroneia yesterday, while scientists remain unsure about what has killed up to 28,000 birds in the area over the past 10 days. Only fish died yesterday. At least 29 types of birds, including protected varieties, have died since the disaster was first discovered on September 8. People, especially children, have been warned to stay away from the area and fishing had already been banned in the lake, which is some 20km (12 miles) east of Thessaloniki. Experts, who have been conducting tests all week, are no closer to finding the cause of the deaths, although some kind of toxin, caused by pollution, in the lake’s water is thought the most likely source. Thessaloniki Prefect Panayiotis Psomiadis, in coordination with other authorities, has ordered that samples of dead birds’ blood, the lake’s water and dead fish be sent to a special lab in Britain on Monday morning for further tests.