Sirens began to sound across Belgrade early in the evening on March the 24th, 1999. Over the next 78 days NATO kept up a relentless bombing campaign. For the first time in more than 50 years, European powers had attacked another European country.The Western nations justified their military action as necessary to try to stop a humanitarian catastrophe in Kosovo. It demanded that Serbia immediately stop its repression of civilians. Belgrade argued that no one else had the right to interfere in what it called an internal problem. A month into the bombing and Serbian television was among the targets of NATO bombs. Commercial buildings, schools, health facilities, cultural monuments and churches were also destroyed or heavily damaged. An internatonal row broke out when the Chinese embassy in Belgrade was attacked. Amid protest from Beijing, NATO insisted the bombing had been a mistake, with outdated maps given as the reason. An armistice came into force on the 10th of June. Yugoslav military and police withdrew from Kosovo after an agreement was signed between Serbian and NATO commanders. As NATO troops rolled into Kosovo, many Serb civilians also left the territory. As well as the grim process of confirming the high number of casualties and widespread destruction, diplomats faced the daunting task of trying to find a lasting political solution.