Serbian police have filed charges against former President Slobodan Milosevic and several of his allies in the abduction and killing of a Serbian ex-president, officials said Thursday.

Police investigating the March 12 assassination of Prime Minister Zoran Djindjic found the remains of former Serbian President Ivan Stambolic last month. Stambolic was once Milosevic's mentor, but the two politicians later became bitter rivals.

Stambolic had been missing since he was abducted in August 2000 while jogging in Belgrade. He disappeared just weeks before a presidential election in which Stambolic was preparing to challenge Milosevic.

"We have evidence that Milosevic suggested Stambolic's 'permanent removal,"' said the police source, speaking on condition of anonymity.

Belgrade district prosecutor Nenad Ukropina told reporters that police have filed charges against nine people, including Milosevic and his former state security chief, Radomir Markovic.

The police official said Milosevic and Markovic are accused of "inciting" the Stambolic slaying.

The actual killing was carried out by members of an elite, paramilitary police unit loyal to Milosevic, the official added.

Police say the paramilitaries took Stambolic to a forest in northern Serbia and shot him in the head. Stambolic served as Serbian president from January 1986 to December 1987.

The official said there was also evidence indicating that Milosevic's wife, Mirjana Markovic, was involved in the Stambolic killing. She is wanted for questioning in the case and is believed to be hiding in Russia. The official refused to say whether police planned to file charges against her.

Milosevic's son Marko, who has been charged with assault in an unrelated case, is also believed to be hiding in Russia.

Milosevic is on trial at the U.N. war crimes tribunal in The Hague, Netherlands, for his role in the wars in Bosnia, Croatia and Kosovo.

In a letter from his prison cell, Milosevic lashed out at Serbian authorities demanding "an end of brutal persecution of my wife and son." The undated letter, sent to the media Wednesday by Milosevic loyalists, also accused Serbian authorities of supporting organized crime.

"The recently arrested criminals and assassins are the same people who helped current government to topple me ... They are the same masked gunmen who abducted and extradited me," said the letter, addressed to a group that fights for Milosevic's release.

Milosevic and Stambolic were close allies in communist-era Yugoslavia. Stambolic promoted Milosevic's rise in the Communist party. But in September 1987 Milosevic orchestrated a party coup against his mentor, taking over the Serbian party leadership.

Stambolic's disappearance remained a mystery in Serbia even after Milosevic's ouster in October 2000 and his extradition to The Hague a year later.

The extensive crackdown on organized crime that followed the Djindjic assassination lead to new leads in the Stambolic case and a separate attempt to kill an opposition leader, police say.

Police accuse Milorad Lukovic, a top suspect in the Djindjic slaying who remains at large, of also organizing the slaying of Stambolic. Lukovic was the commander for the paramilitary police unit before it was disbanded last month.

Authorities on Tuesday lifted a state of emergency imposed after Djindjic's assassination, saying the killing had been fully solved.

More than 10,000 people have been detained in the past 40 days, 4,500 of whom remain in custody, said Sreten Lukic, the assistant interior minister.