( CNN ) -- U.S. Secretary of State John Kerry is sending a special envoy to South Sudan following an escalation of violence in the world 's newest nation . Ambassador Donald Booth , the special envoy to Sudan and South Sudan , headed to the area Friday . `` Now is the time for South Sudan 's leaders to rein in armed groups under their control , immediately cease attacks on civilians , and end the chain of retributive violence between different ethnic and political groups , '' Kerry said in a statement . `` The violence must stop , the dialogue must intensify . '' Also on Friday , National Security Adviser Susan Rice recorded an audio message to the people to South Sudan . `` I ask each of you to make the choice for peace -- make the choice for a unified and cohesive South Sudan , '' she said . `` Make this choice for yourselves and your children . '' Attackers killed two Indian army peacekeepers in South Sudan and wounded a third one in the chest , the United Nations said Friday . At least two of the 30 civilians who took refuge at the United Nations ' Akobo base were killed in the attack Thursday , said Joseph Contreras , the U.N. spokesman for South Sudan . It could have been as many as 20 who died in that attack U.N. officials estimated . Their remains will be taken to the capital of Juba . Deadly clashes have raged South Sudan for days after a reported coup attempt in the capital over the weekend . President Salva Kiir blamed soldiers loyal to his former vice president , Riek Machar , for starting the violence . Casualties are in the hundreds , including soldiers , the government said . The government of neighboring Kenya will send troops into South Sudan to help evacuate 1,600 Kenyan citizens , presidential spokesman Manoah Esipisu said . An official from South Sudan 's ruling party , who has just left the country , said the U.S. is not doing enough . `` There was a lot of presence of troops in the city . There was a lot of injured , displaced people . Gunshots heard every two minutes , a lot is at stake , a lot needs to be done , '' said Choul Laam , chief of staff for the secretary general of the ruling SPLM Party . `` President Barack Obama made a statement and is dispatching a special envoy to the area . I believe that 's not enough . A lot of dialogue needs to be taking place . A lot of convincing needs to be taking place . '' Obama sent 45 service members to South Sudan to support U.S. personnel and the American Embassy . `` In 2011 , millions of South Sudanese voted to forge a new nation , founded on the promise of a more peaceful and prosperous future for all of South Sudan 's people , '' Obama said in a prepared statement . `` In recent years , against great odds , South Sudan has made great progress toward breaking the cycle of violence that characterized much of its history . `` Today , that future is at risk . South Sudan stands at the precipice . Recent fighting threatens to plunge South Sudan back into the dark days of its past , '' the President said . Tensions have been high in South Sudan since Kiir dismissed his entire Cabinet , including Machar , in July . The move inflamed deep tensions between Kiir 's Dinka community and Machar 's Nuer community . U.N. officials have said they are worried the recent fighting is based on ethnic divisions , but the government has disputed that assertion . Eleven people have been arrested in connection with the foiled coup . CNN 's Zain Verjee and Clare Hayes contributed to this report .
Kerry dispatches Special Envoy Donald Booth to South Sudan . Fighting grows after a reported coup attempt in Juba over the weekend . Unknown assailants attack a U.N. base in world 's newest nation . Two civilians who took refuge at the base are also killed .