LONDON: Britain was sending a second flight on Friday to evacuate its nationals from South Sudan amid spiralling violence in the fledgling nation, the Foreign Office said.

On Thursday, a Royal Air Force C-17 military transport plane successfully evacuated 182 people, including 53 British nationals, out of the country to Uganda, officials said.

Foreign Secretary William Hague welcomed the evacuation and said he was “very concerned” about Thursday’s assault on a United Nations base, which left three Indian peacekeepers dead.

“Very concerned by attack on UN peacekeeping base in South Sudan and sad loss of life. Urge restraint and an end to the violence,” he said on Twitter late Thursday.

Britain and the United States have both pulled some of their embassy staff out of the country and have urged their nationals to leave.

The Foreign Office told those hoping to board Friday’s evacuation flight to pack light, warning: “If you bring baggage to the airport, you may have to leave it there.”

It added: “We strongly advise all British nationals in South Sudan to leave the country if they can do so safely.

“You may have difficulty leaving in the event of a further deterioration in security.”

US President Barack Obama has warned that South Sudan stands on the “precipice” of civil war.