U.N. Secretary-General Kofi Annan called on the international community Monday to create a "bulwark against evil" by establishing a permanent world criminal court.

In opening the five-week U.N. conference to set up the tribunal, he appealed for a "court strong and independent enough to carry out its task" of bringing war criminals and perpetrators of crimes against humanity to justice.The United States, Russia, China and France - four of the five permanent Security Council members - have been pushing for stronger council control over the proposed court's prosecutor. Human rights advocates say that would cripple the court's independence.

"People all over the world want to know that humanity can strike back - that wherever and whenever genocide, war crimes or other such violations are committed, there is a court before which the criminal can be held to account," Annan told the delegates.

"We have an opportunity that can save lives and serve as a bulwark against evil."

He told reporters that it was more important to have a "credible, competent, independent" court that may have fewer signatories than a broadly supported weak one.

"Sooner or later (other nations) will come aboard. If it is ineffectual, no one gains and in fact this would be a waste of our time," Annan told a news conference.

Meanwhile, in another reminder of why a permanent court is necessary, NATO forces Monday arrested a Bosnian Serb war crimes suspect near Sarajevo, accused of atrocities committed at a prison during the war.

A court has been set up on a temporary basis in The Hague for Yugoslav war crimes. The world tribunal would supersede such courts.

The road to a world court is sure to be long and hard. Success is by no means certain.

Delegates from more than 180 nations must wrestle with basic issues, such as the powers granted the prosecutor, what will set a prosecution in motion, how much influence the U.N. Security Council and its members will have over the court's functioning and what crimes it will cover.

Britain, alone among the Security Council permanent members, seeks more independence for the court. "We hope the United States will get on board," said Tony Lloyd, the British minister of state for foreign affairs.

All parties basically agree that the court will target genocide, war crimes and crimes against humanity. Defendants will be individuals, unlike at the existing International Court of Justice at The Hague, where nations lodge complaints against nations.

The court would take on a limited number of cases and not duplicate national efforts.