Bulgarian authorities have detained a former Kosovo prime minister on an international arrest warrant issued by Interpol at Serbia's request. Police say Agim Ceku, the prime minister of Kosovo between 2006 and 2008, was taken into custody at the Gyueshevo border checkpoint while entering Bulgaria from Macedonia late Tuesday. Ceku, 59, is wanted for war crimes allegedly committed during the 1998-1999 war when he was military chief of the Kosovo Liberation Army, The Associated Press reported. The prosecutor's office said Ceku will be held in custody in the western city of Kyustendil, where the district court will consider his case. In Pristina, Kosovo authorities said they have been in contact with Bulgarian officials to negotiate Ceku's release. Ceku's arrest comes despite repeated requests from U.N. officials in Pristina that the Belgrade-issued arrest be disregarded. Most recently Ceku was deported from Colombia. Before that he was held overnight in prisons in Slovenia in 2003 and Hungary in 2004. Kosovo proclaimed independence last year and was recognized by leading Western nations, including the United States and most of the European Union nations, including Bulgaria.