At least 20 people are dead after an armed mob stormed a United Nations base in South Sudan, Reuters reported.  

In addition to the deaths, dozens more were injured as the mob barged their way through the UN compound in the northern state of Jonglei, which was protecting members of the minority ethnic group Nuers, the Associated Press reported. The mob, mostly young civilians, arrived at the base under the pretext of delivering a petition to the UN before they launched an assault on the ethnic group.

Stephane Dujarric, a UN spokeswoman, told Reuters that the exact number of fatalities and those who were wounded could not yet be confirmed. Those injured were treated at the compound.

Thousands of Nurs have sought refuge at the UN base after fleeing their homes when violence broke out in the country in December 2013, the Associated Press reported. The violence rose between troops who support President Salva Kiir and forces that support the deposed Vice President Riek Machar. Over one million have been displaced.

"This attack on a location where civilians are being protected by the United Nations is a serious escalation," Dujarric told Reuters. "The assailants- a mob of armed civilians- came to the base under the guise of peaceful demonstrations intending to present a petition to UNMISS," said Dujarric, referring to the UN peacekeeping mission.

"The armed mob forced entry on to the site and opened fire on the internally displaced persons sheltering inside the base. At the time of the attack there were some 5,000 displaced civilians...inside the base."

South Sudan, which formed in 2011 when it seceded from Sudan, has seen a continuation of violence even after both sides agreed to a ceasefire at the end of January.

Troops from Uganda have now been deployed to protect the UN base, South Sudan military Major Kuol Mayen Deng told the Associated Press.