The top prosecutor of the International Criminal Court on Tuesday welcomed judges' decision to send four prominent Kenyans to trial over election-related killings.

"It's a very good decision and we are preparing for trial," Luis Moreno-Ocampo told a press conference at the court's headquarters in The Hague.

Deputy Prime minister Uhuru Kenyatta and former minister William Ruto, both of whom are candidates in Kenya's upcoming presidential elections, will be tried for crimes against humanity along with two others, radio host Joshua arap Sang and civil service chief Francis Muthaura.

Moreno-Ocampo told reporters that the prosecution would not appeal the court's decision to drop charges against another former minister, Henry Kosgey, and former police chief Muhammed Hussein Ali.

The prosecutor praised Kenya's co-operation with the court, saying it was showing the world "a new standard how to handle conflict differently."

The charges related to the violence related to the 2007 presidential elections in which more than 1,000 people were killed and 600,000 displaced.

What began as political riots after the December 2007 vote soon turned into ethnic killings targeting Kenyatta's Kikuyu tribe.

The Kikuyu launched reprisal attacks in which homes were torched and people hacked to death in the worst outbreak of violence since independence from Britain in 1963.