Serbia's Supreme Court has affirmed the 40-year prison sentences for the ringleaders in the 2003 assassination of the country's first democratically elected prime minister, Zoran Djindjic.

Former Serbian Prime Minister Zoran Djindjic (file photo)

Paramilitary commander Milorad Ulemek, who headed the notorious Red Berets unit under former President Slobodan Milosevic, was found guilty in 2007 of organizing the assassination.

The unit's deputy commander, Zvezdan Jovanovic, was found to be the triggerman in the assassination, which occurred outside Serbian government headquarters in Belgrade.  The 40-year sentences are the maximum allowed under Serbian law.

The Associated Press says the court reduced the sentences of three other convicted participants, while upholding the prison terms of seven others.

A trial judge in 2007 called the Djindjic assassination a political murder aimed at stopping the prime minister's pro-Western reforms. 

The judge also said the conspirators were seeking to bring Milosevic allies back to power, and to stop the extradition of war crimes suspects to the United Nations war crimes tribunal in The Hague.

Some information for this report was provided by AP.