During 5 February the fiercest fighting in the Preševo valley happened since the end of the 1999 Kosovo conflict . The Yugoslav army exchanged artillery fire for several hours across the internationally-imposed buffer zone next to the border with Kosovo.On 16 February near the border town of Podujevo 7 Serb civilians were killed after Niš-Ekspres bus with refugees from Kosovo was blown up by PMBLA . After that , on 7 March 2001 , KFOR agreed to allow Serb military to reoccupy buffer zone ( called " Ground Safety Zone " ) section by section . At the same time Albanian guerrillas started mutiny in Republic of Macedonia . During the March one-week ceasefire was agreed again , after four policeman were killed . Army first entered the section on a border with FYR Macedonia ( section '' ' C East ' '' ) , in order to stop illegal arms smuggling . Afterwards KFOR allowed Serbs to return to zones '' ' C West ' '' and '' ' A ' '' on 25 March , and zone '' 'D ' '' on 14 April . On 21 May Albanian commanders signed Končulj agreement and agreed to disarm , but many continued to fight . Last section was around Preševo ( sector '' ' B ' '' ) . On 24 May Serbian army entered the town , although Albanian fighters were attacking them . There , one of the rebel commanders , Ridvan Qazimi " Lleshi " was killed . It is not clear whether he was killed by police or by other insurgents . After Serb victory UÇPMB agreed to disarm . Some of its veterans joined newly formed National Liberation Army in Republic of Macedonia . Around 400 guerrillas surrendered in order to get the pardon from the Yugoslav government . PMBLA chief Shefket Musliu surrendered to KFOR on 26 May . Until August 2001 there were around 1,160 attacks on Serb police and civilians
was blown up
Podujevo bus bombing
Insurgency in the Preševo Valley