AFP - A divided Serbia marks the 10th anniversary Tuesday of NATO's bombing campaign against it over Kosovo with commemorations organised by its pro-West government and a separate nationalist rally.
   
Serbian President Boris Tadic described the NATO intervention as a "tragic military campaign" in a speech on the eve of the anniversary before the United Nations Security Council in New York.
   
NATO launched the strikes on March 24, 1999 -- without Security Council backing -- after late president Slobodan Milosevic refused to sign up to a peace deal to end his forces' violent crackdown on separatist Kosovo Albanians.
   
By the time Milosevic eventually conceded 78 days later, paving the way for NATO to enter the disputed territory of Kosovo, the civilian death toll from the bombing campaign was put at around 500 by Human Rights Watch.
   
"The lesson for Serbia is that it must not get into a situation in which its citizens are punished and killed ever again," Tadic told the Security Council.
   
"Some 2,500 civilians were killed, among them 89 children, while 12,500 were injured," said Tadic, whose governing Democratic Party opposes Kosovo's independence, but not at the expense of the country's integration with the European Union.
   
Some 15,000 NATO-led peacekeepers remain in Kosovo, which 56 nations recognise after its ethnic Albanian-dominated parliament declared unilateral independence from Serbia 13 months ago.
   
As part of Tuesday's commemorative events, Serbian schools will begin the day with a minute's silence, followed by a special cabinet session and the midday (1100 GMT) sounding of air-raid sirens that used to signify the end of the bombing sorties.
   
Ministers will gather at the same time to lay wreaths at spots where people were killed during the 11-week air war -- at the time the biggest military operation in NATO history.
   
Separately, a hardline nationalist group plans to stage an anti-NATO rally in the main square of Belgrade, according to posters that have gone up around Serbia's capital.
   
"Better war than NATO" membership, say some of the posters seen in underground passageways of the city, where similar protests against Kosovo's formal secession from Serbia turned violent last year.
   
Serbia estimates that NATO's 78-day bombing campaign cost it 30 billion dollars from direct damage caused by its bombs and missiles.
   
Health concerns also still remain about the danger to civilians from weapons NATO used during the campaign.
   
Thousands risk life and limb from 2,500 cluster bomblets still scattered across Serbia, while the use of weapons with cancer-causing depleted uranium has killed dozens of Italian soldiers alone, according to European non-governmental groups.
   
In 2006, Serbia joined NATO's Partnership for Peace programme -- a framework for practical cooperation with countries aspiring to join NATO -- but Belgrade has yet to take any steps to join the alliance.