Some 15,000 people in parts of northern Greece have been warned not to drink their tap water as pesticides from a nearby factory may have poisoned the water in their private underground wells, municipal officials said. Diamantis Papadopoulos, mayor of the Thessaloniki suburb of Stavroupolis, yesterday revealed evidence that the 550 tons of pesticides left behind at the now-defunct Diana factory have affected water supplies. Papadopoulos said he had told locals not to drink the water until more tests are done. Initial samples taken by Thessaloniki University found traces of the factory’s chemicals in water reserves. The region is not connected to northern Greece’s water network, so residents get their water through private reserves. The minister of Macedonia and Thrace, Nikos Tsiartsionis, assured local residents that the process of removing pesticides will begin in the next few months. Local officials, however, said something must be done far sooner.