The Greek government reported that seven illegal immigrants died when they stepped on land mines in a minefield between Greece and Turkey. The illegal immigrants had crossed the Evros River (which forms part of the northeastern border between Turkey and Greece). The report did not identify the immigrants' nationality. This has happened before. The Turkey-Greek land border in Thrace remains heavily fortified, just like most of the Greek islands lying close to the Turkish coast. According to Greek sources, at least 40 illegal immigrants have been killed in mine fields since 1996.