The war crimes tribunal in The Hague has called on the United Nations to get tough with Yugoslavia for failing to hand over war crimes suspects.

May I remind you that 11 accused have still not been apprehended or brought before the International Tribunal

Judge Claude Jorda

The request coincides with the visit by the tribunal's chief prosecutor, Carla Del Ponte, to Croatia, to press for the extradition of the country's wartime army chief, General Janko Bobetko, recently indicted for war crimes by The Hague.

Mrs Del Ponte, who is on a tour of the Balkans, said on Tuesday that President Kostunica of Yugoslavia was preventing the arrest of a leading war crimes suspect, Ratko Mladic.

The tribunal's President, Judge Claude Jorda, said both he and Mrs Del Ponte were convinced that the Yugoslav Government was not co-operating in tracking down, arresting and transferring certain key figures.

"The prosecutor and I request that you take all the measures necessary in order to force the Federal Republic of Yugoslavia to assume fully its international obligations," Judge Jorda's statement said.

"May I remind you that 11 accused have still not been apprehended or brought before the International Tribunal."

Backlash fears

The Croatian indictment centres around an operation planned and commanded by General Bobetko during the war in Croatia in 1993.

The tribunal wants 83-year old General Bobetko handed over

Witnesses at the time reported seeing General Bobetko's troops torturing and murdering local civilians.

The case is gripping Zagreb.

National newspapers have printed posters of the retired chief of staff, and sales of his autobiography - on which The Hague is thought to have based at least part of the indictment against him - have rocketed.

The Croatian Government says the indictment is unconstitutional.

In response, the British Government has suspended the ratification of an agreement with Zagreb, and there is talk of EU sanctions.

Croatia is expected to point out that the 83-year-old general is too ill to travel to The Hague, to avoid a nationalist backlash.

Change of mood

This case has important ramifications for the whole of the region, says the BBC's Belgrade correspondent Matthew Price.

If Croatia is seen to get away with refusing to co-operate with The Hague, other governments will be less inclined to hand over those indicted in their countries.

Many feel Croatia's refusal so far is due to the fact that the government - already unpopular over other issues - does not wish to risk inciting mass protest.

When the indictment against General Bobetko was first announced, the vast majority of the population appeared to back the government's stance.

But as talk of sanctions against Croatia grows, there appears to be a change of mood.

Surveys now show while a majority still support the general, some are starting to argue he should go to The Hague to defend himself and his country.