Chief Prosecutor Louise Arbour: "This is not a fresh indictment but one kept under seal"

The tribunal said Arkan - whose real name is Zeljko Raznjatovic and whose men are held responsible for some of the worst massacres in recent Balkan conflicts - had previously been on a sealed list of war crimes suspects.

"In light of recent reports of his alleged involvement in Kosovo. I have decided to make public the existence of an indictment against...Arkan," said the tribunal's chief prosecutor Louise Arbour.

Ms Arbour said the announcement was intended as an "unambiguous signal" to Arkan's associates.

Louise Arbour: Sending a message to Arkan's associates

"If the public disclosure of this arrest warrant reduces somewhat the possibility of his arrest outside Yugoslavia, it will nevertheless serve to put on notice those who might be inclined to retain his services or to obey his orders that they too will be tainted by their association with an indicted war criminal," she said.

The arrest warrant had been issued already in 1997, but UN prosecutors have adopted a policy of keeping indictments under seal to facilitate arrests.

Ms Arbour said the court order to make the warrant public did not apply to details of the indictment itself. The document would remain sealed until Arkan's arrest.

Charges of atrocities

Arkan is leader of a paramilitary group known as the Tigers, alleged to be responsible for atrocities that were carried out in Vukovar in Croatia and at Bijeljna in Bosnia at the start of the break-up of the former Yugoslavia.

In the last few days, Arkan has been reportedly been seen in Kosovo, but in interviews he has said that his men would only go to the Serbian province if Nato ground troops set foot on Yugoslav soil.

He was recently seen in Belgrade, where he was quoted as saying that his men might go to Kosovo if Nato ground troops set foot on Yugoslav soil.