The US has flown three groups of its citizens out of South Sudan and continues to urge other Americans to evacuate the country, after heavy violence broke out that the Department of State called "deeply troubling." The government in Juba has put the death toll at around 500, as rebels fought security forces and wounded another 800 people during clashes. South Sudan President Salva Kiir said his forces foiled a coup attempt. The US on Wednesday called on "the country's political leaders to refrain from any action that could escalate an already tense situation or fuel the violence." "It is absolutely critical that political differences be resolved by peaceful and democratic means," said State Department Deputy Spokesperson Marie Harf in a statement. She noted that the US ambassador to South Sudan, Susan D. Page, has met with Kiir "to discuss our concern about the continued violence, increasing death toll, and growing humanitarian challenges." "She raised the arrests of several opposition members and called on the government to ensure their rights are protected in accordance with South Sudan's constitution and international humanitarian and human rights laws and norms.