Russia 's foreign minister calls on South Sudan to punish those responsible . The Sudan People 's Liberation Army said it was an accident , according to spokesman Philip Aguer . Four Russians died when South Sudanese forces shot down a U.N. helicopter . South Sudan 's armed forces say the incident was an accident . Comment:
Russia 's foreign minister calls on South Sudan to punish those responsible . Four Russians died when South Sudanese forces shot down a U.N. helicopter . South Sudan 's armed forces say the incident was an accident . Comment: