NAIROBI, Jumada II 19, 1435, Apr 19, 2014, SPA -- A fresh offensive by South Sudanese rebels this week aims to seize oil fields and towns with oil installations to starve the government of funds for its war chest, Reuters cited a rebel spokesman as saying on Saturday, Reuters reported. James Gadet Dak, spokesman for rebel leader Riek Machar, said oil revenues helped President Salva Kiir engage Ugandan troops and Sudanese militias to keep him in power and delay the start of peace negotiations agreed in a ceasefire in January. Rebel troops seized control of Bentiu, capital of the oil producing Unity State, on Tuesday. Fighting has continued in the area but poor communications make it difficult to confirm claims of further fighting by the rebel or government sides. Once in control of Bentiu, the rebels told oil firms there to pack up and leave within a week after they recaptured Bentiu. Oil firms operating in South Sudan include China National Petroleum Corp, India's ONGC Videsh and Malaysia's Petronas. "We are targeting the oil fields because we want to stop Salva Kiir from using the oil revenues to finance the war and renting foreign forces, particularly Ugandans and other Sudanese rebels which are allied to Salva Kiir's forces," Gadet said. "This is to put pressure on Salva Kiir to talk peace in good faith and if he does not heed to that we are coming to Juba to depose him," he added. The cessation of hostilities agreement signed on Jan. 23 had largely held until this week, except for isolated skirmishes. The talks on a comprehensive political settlement that were agreed back then have been delayed several times as the two sides haggle over preliminary details. They are now due to start in Addis Ababa in neighbouring Ethiopia on April 23. -- SPA 20:27 LOCAL TIME 17:27 GMT www.spa.gov.sa/1222400