Although crime rates decreased in 2003, violence and crimes against minorities were concerning. On 12 April 2003 a bomb exploded on a railway bridge in Northern Kosovo, killing two, including the planter, a KPC officer; an Albanian extremist organization took responsibility. On 17 April the Special Representative defined the group as terrorist. On 19 May a Kosovo Serb politician from Klokot was murdered and two elderly Serbs assaulted. On 4 June three Kosovo Serbs were murdered in Obilić. In August 2003, explosive devices planted in the Serb enclave of Klokot destroyed five Serb houses, with several injuries, including two American KFOR soldiers. On 13 August two Serb youths were killed and four wounded in a shooting in Goraždevac. On 18 August a Serb male died from wounds sustained from a shooting on 11 August, and another was seriously wounded in a shooting in a returnee site near Klina. On 31 August, four Serbs were injured and one killed in an explosion attack in Cernica near Gnjilane. The violent incidents further heightened the feeling of insecurity in the Serb minority, while UNMIK police took security measures in minority areas. Crime against UNMIK increased, with a police officer killed in the north by sniper on 3 August, while a KPS officer was murdered near Djakovica on 6 September, and another KPS officer was shot at in Pristina on 10 September. The violence level increased steadily since late 2003. On 17 March 2004, a violent unrest broke out in Kosovo.