The United Nations has begun to relocate "non-critical" staff from South Sudan to neighbouring Uganda, dpa reported. The UN mission in South Sudan (UNMISS) said it had already moved all civilian staff from Bor - the capital of Jonglei state, where rebels killed two peacekeepers - to Juba. There are plans to boost the number of troops in Bor. Plans are also underway to evacuate non-critical staff from Unity state, which has largely fallen under rebel control, and reinforce the number of peacekeepers there. "We are not abandoning South Sudan," said Hilde Johnson, the UN's top official in the country. "To anyone who wants to threaten us, attack us or put obstacles in our way, our message remains loud and clear: we will not be intimated."