JUBA, July 11 -- Gunfire erupted again in Juba, capital of South Sudan, on Monday, raising fears of an escalation in fighting between soldiers loyal to President Salva Kiir and those supporting First Vice President Riek Machar, according to media reports.

At least 271 have been killed in the fighting since its eruption on Thursday, and the United NationsSecurity Council has urged the rival leaders to rein in their forces and end the violence.