The Siege of Sarajevo began on April 5, 1992 as the longest siege of a capital city in modern history. Over 100,000 people were killed during the nearly four-year siege by Bosnian Serb forces. Key events included the Bosnian deputy prime minister being killed by Serbian forces in January 1993 and 68 people being killed when a mortar shell hit a market in February 1994. The UN helped establish a brief ceasefire in late 1994 to allow for a peace agreement to be signed, though they did not intervene militarily until late in the conflict.