Three Irish aid workers are among thousands seeking refuge from escalating violence in the South Sudanese capital of Juba.

The Concern Worldwide staff are said to be on lockdown after gun battles erupted in and around the city on Friday.

Feargal O’Connell from Dublin, the charity’s country director, is in hiding with six other staff at Concern’s office in Juba.

He told Newstalk last night that up to 10,000 people may now be displaced. 

Working with finance head Admasu updating spreadsheet to track location of colleagues. Shouldn't be this way. pic.twitter.com/1IPBnvzyK3

— Feargal O'Connell (@FeargalConcern) July 10, 2016

Two other Irish citizens working with Concern are in field locations outside the capital of the world’s newest country, which has been beset by civil war since 2013.

Hundreds are reported to have died in gun battles since the renewed outbreak of fighting between government soldiers supporting President Salva Kiir and troops loyal to Vice-President Riek Machar.

The UN Security Council has condemned the violence "in the strongest terms" and urged warring groups to control their forces. It also criticised the targeting of UN compounds housing displaced citizens.

The council called on South Sudan's two opposing leaders to “genuinely commit themselves to the full and immediate implementation of the peace agreement, including the permanent ceasefire and redeployment of military forces from Juba”.

The Department of Foreign Affairs has meanwhile warned Irish citizens against travelling to the country. 

Minister Charlie Flanagan said yesterday that he was “very concerned” at the deteriorating security situation in Juba.

”My department is monitoring the situation closely and our embassy team in Addis Ababa is liaising with Irish citizens in the area who are registered with the department,” he said.