A former prime minister of Kosovo, Agim Ceku, has been arrested by Bulgaria.Officials on the Macedonian-Bulgarian border used an Interpol arrest warrant issued by Serbia for alleged war crimes. The Kosovo government has urged Interpol and other countries to ignore Serbia’s warrant. This is the fourth time Ceku has been stopped in several countries, but he has never been handed over to Belgrade. Ceku was a former commander of Kosovo Albanian fighters during the 1988-99 war. He is accused of war crimes against Serbs in Kosovo and also during the war in Croatia. Bulgaria says Ceku’s detention has been extended until Saturday. Serbian officials have been requested to present their arguments for extradition to a court in Sofia.