Kenya\'s deputy prime minister and another presidential hopeful are among four suspects who should be tried over deadly post-poll unrest four years ago, the International Criminal Court ruled Monday. Kenya\'s President Mwai Kibaki appealed for calm in the east African country amid fears the Hague-based court\'s anxiously awaited confirmation of charges hearing could revive ethnic and political tensions. The ICC said charges of crimes against humanity had been confirmed against William Ruto and Uhuru Kenyatta, the son of the country\'s founding president, dropping a bombshell in Kenya\'s presidential campaign. Finance Minister Kenyatta pledged to cooperate with the ICC but stressed his innocence in the violence that erupted following a disputed 2007 presidential vote, while Ruto dismissed charges against him as \"strange.\"  More than 1,100 people died in the violence, shattering Kenya\'s image as a beacon of regional stability. \"The chamber found that there are substantial grounds to believe Mr Ruto is responsible as an indirect co-perpetrator of the crimes,\" ICC presiding judge Ekaterina Trendafilova said before a public hearing. \"In regards to Mister... Kenyatta, the chamber was satisfied that the evidence established that there are substantial grounds to believe that (he is) criminally responsible of the alleged crimes, as an indirect co-perpetrator.\" Two other Kenyans, radio host Joshua arap Sang, 36, and Francis Muthaura, 65, the head of Kenya\'s civil service, will also face trial. Charges were dropped against former industrialisation minister Henry Kosgey and former police chief Mohammed Hussein Ali, the court said. Nairobi had sought to pre-empt the impact of the ICC\'s decision saying that appeals were possible, while Kibaki asked for calm. \"I appeal to everyone to remain calm and peaceful. Our great nation has had its share of challenging times,\" Kibaki said Monday in a public statement.  ICC chief prosecutor Luis Moreno-Ocampo was allowed in March 2010 to investigate the six, three of them aligned with Kibaki\'s Party of National Unity and three who supported the opposition Orange Democratic Movement of Raila Odinga, now the prime minister in a coalition government. Odinga, also a leading presidential hopeful, said he hoped that the \"final outcome will deliver justice to both the Kenyan nationals before the ICC and the victims of post-election violence.\" Observers had feared the ruling could trigger fresh violence, four years after election fraud allegations sparked Kenya\'s worst unrest since independence and revealed deep ethnic rifts. However the ICC\'s decision predictably struck a perfect balance between the two rival camps. Ruto and Sang were opposition supporters in 2007, while Kenyatta and Muthaura were and still are Kibaki allies. \"I am innocent of all the accusations that have been leveled against me. I have cooperated with the ICC throughout the process and will continue to do,\" Kenyatta said. Ruto maintained his innocence, adding that he would still run for the presidency. A fresh presidential election in the east African country is due by March 2013 at the latest. Kenyan and international legal organisations welcomed the ruling on the four men, but rights groups urged Nairobi to investigate other perpetrators as well. \"Thousands of human rights abuses, some of which may amount to crimes against humanity, took place during the post-election period and thousands of victims are still waiting for justice,\" Amnesty International in a statement.  Kenyatta, also a deputy prime minister, and Muthaura, often described as Kibaki\'s right-hand man, face five counts including orchestrating murder, rape, forcible transfer and persecution in the polls\' aftermath. Kenyatta, 50, has been accused of ties with the shadowy criminal gang called the Mungiki -- a sect-like body known for skinning and beheading its victims -- which he allegedly directed to attack opposition supporters. Ruto, 45, and radio boss Sang, face three counts of murder, forcible transfer and persecution. They are accused of \"carefully orchestrating\" attacks against ruling PNU supporters after Odinga charged Kibaki was rigging his way to reelection. Sang also rejected the charges, while Muthaura\'s lawyer Karim Khan said his client was innocent and would be appealing. What began as political riots after the December 2007 vote soon turned into ethnic killings targeting Kenyatta\'s Kikuyu tribe. This launched reprisal attacks in which homes were torched and people hacked to death in the worst outbreak of violence since Kenya acquired independence from Britain in 1963.