More than 60,000 South Sudanese have entered Sudan in the first three months of 2017, the UN refugee agency said on Wednesday, fleeing famine and war in the world's youngest nation.
South Sudan, formed after splitting from the north in 2011, has declared a famine in parts of the country where 100,000 people are said to be facing starvation.
The UN refugee agency UNHCR was initially expecting 60,000 South Sudanese refugees to arrive in Sudan in the whole of 2017, but that figure has already been exceeded in the first three months.
"The number of new arrivals has surpassed expectations, signalling a likely worsening situation in South Sudan," it said in a statement.
UNHCR anticipates a continuous influx of South Sudanese refugees throughout this year, but is concerned about a drop in funding to meet their needs.
Aid groups have denounced a "man-made" famine caused by bloodshed in South Sudan where civil war has forced people to flee, disrupted agriculture, sent prices soaring and cut off aid agencies from some of the worst-hit areas.
South Sudan has been engulfed by war since 2013 after President Salva Kiir accused his rival and former deputy Riek Machar of plotting a coup.
More than 365,000 South Sudanese refugees, most of them women and children, have arrived in Sudan since December 2013.