Between 60,000 and 90,000 people have fled from Sudan to neighbouring Chad since violence erupted last month, the U.N. refugee agency said on Monday.
More than 250,000 people have crossed the borders to neighbouring countries since the conflict broke out, with more expected to flee as fighting continues.
"Almost 90% of new arrivals are women and children. Many have been sheltering under trees in makeshift shelters with very limited services," said UNHCR's Assistant High Commissioner for Operations Raouf Mazou after a four-day visit to Chad.
"As the rainy season approaches, we urgently need to relocate new arrivals to the nearest refugee camps," he said in a statement issued in N'Djamena.
The new arrivals have added to around 600,000 mostly Sudanese refugees already present in Chad after fleeing previous conflicts.
Chad is now hosting almost 700,000 refugees in total, the UNHCR said, urging more international support for displaced people from Sudan.
The U.N. Food Programme said earlier this month that it needed $162.4 million to support the government of Chad in assisting 2.3 million people in urgent need of food.
(Reporting by Sofia Christensen; Editing by Cynthia Osterman)
