United Nations Mission in South Sudan or UNMISS expressed deep concern over the fighting that broke out in Juba on Sunday and continued until Monday.
In a statement issued on Monday, UNMISS head Hilde Johnson called on all parties to cease hostilities immediately and exercise restraint.
She hoped the security situation in Juba will quickly normalize to enable civilians to return to their residential areas very soon.
Ms Johnson confirmed that hundreds of civilians mostly women and children sought refuge in its compound near Juba international airport and at UN House in the Jebel Kujur area.
UNMISS head denied harbouring key political or military figures.