(BRUSSELS) - The European Union should not allow its leading candidate nation Croatia to join up unless Zagreb ends impunity for war crimes, Amnesty International's head said Tuesday.

London-based rights group Amnesty complains that though there have been a number of war crimes trials in Croatian courts related to the 1991-95 war, these were essentially linked to victims who were ethnic Croats.

"There are huge problems inside Croatia still, particularly on investigating and prosecuting crimes at a local level when the victim is Serbian," Amnesty's Secretary General Irene Khan told AFP in Brussels.

Croatia, which began its EU accession talks in October 2005, has so far opened 16 of the 35 chapters or policy areas that it must complete in order to join the bloc, putting it in pole position to become the next member state.

The government in Zagreb hopes to close all of the negotiating chapters by 2009 and become the 28th member of the European Union the following year.

Khan argued that the key justice chapter should not be closed until the judicial problems had been addressed.

"When they open the justice chapter they need to make sure that the issues of judicial reforms, the issues of addressing impunity in an impartial way are addressed before the chapter is closed," said Khan, who was due to meet EU officials later.

Brussels has warned Zagreb that its EU ambitions could be jeopardised by delays to reforms of its justice system and public administration.

Croatia is the first candidate nation where the European Union has "had to deal with war crimes and post-conflict issues," said Khan.

"How the EU deals with Croatia will set the stage for others. It will also set the stage for greater regional stability in the Balkans," she added.

"It is very important that (the EU) does not allow these important issues of war crimes to be brushed under the carpet."

Croatia's proclamation of independence from the old Yugoslav federation in 1991 sparked the four-year conflict with rebel Serbs who opposed the move.

The war left some 20,000 people dead.

Text and Picture Copyright 2008 AFP. All other Copyright 2008 EUbusiness Ltd. All rights reserved. This material is intended solely for personal use. Any other reproduction, publication or redistribution of this material without the written agreement of the copyright owner is strictly forbidden and any breach of copyright will be considered actionable.