US President George Bush has urged Americans to do more to promote racial equality, as the country honoured the murdered civil rights leader, Martin Luther King.

  "There are still people in our society who hurt," Mr Bush said at a service in the predominantly black First Baptist Church of Glenarden in Maryland.

His comments came just days after he said the government would back a court action to oppose favouring black students in university admissions.

US Secretary of State, Colin Powell, has criticised Mr Bush's decision, saying so-called "affirmative action" policies were necessary.

Mr Bush's announcement has also triggered a new debate on one of the most contentious issues in America, since the policies were adopted in the 1960s.

'Race-neutral' dream

"Even though progress has been made, there is more to do," Mr Bush said in his Martin Luther King Jr Day speech.

"There's still prejudice holding people back. There is still a school system that doesn't elevate every child so they can learn," he said.

Mr Bush's appeal followed his decision last week to back three white students who are suing the University of Michigan because black and Hispanic applicants were given extra points towards admission.

The president said Michigan's reliance on race in determining admissions was "divisive, unfair and impossible to square with the constitution".

But his move angered many black community leaders and politicians across the country.

"I'm a strong believer in affirmative action," Mr Powell, the first African American Secretary of State, told CBS television's Face the Nation programme on Sunday.

He later told CNN's Late Edition: "I wish it was possible for everything to be race-neutral in the is country, but I'm afraid we're not yet at that point."

Calls for peace

Meanwhile, the widow of Martin Luther King urged President Bush to follow the civil rights leader's commitment to peace and non-violence in solving the Iraq crisis.

"We commemorate Martin Luther King as a great champion of peace, who warned us that war is a poor chisel for carving out peaceful tomorrows," Corretta Scott King said.

"May his challenge and his example guide and inspire us to seek peaceful alternatives to a war with Iraq," she added at a memorial service at King's Ebenezer Baptist Church in Atlanta.

Martin Luther King won the Nobel Peace Prize in 1964 for his efforts to help black Americans win equal rights and end the policy of segregation.

He was assassinated in Memphis in 1968.

His memory is honoured across the US on the third Monday in January.