The UN said on Monday that it had identified 19,000 displaced people in Ukraine, while estimates from local authorities indicated another 15,000 had been forced from their homes in areas it does not monitor.
There are "credible reports of movements inside Donetsk and Lugansk provinces . . . including an estimated 15,000 people from Slavyansk," said UN humanitarian affairs chief Valerie Amos.
Donetsk and Lugansk in eastern Ukraine are at the epicentre of a pro-Russia insurgency that began in March and triggered a military operation that has killed more than 300 people.
The UN said last month at least 10,000 people had been driven from their homes since the start of the Ukraine crisis, with Crimean Tatars the hardest-hit.
Thousands of Crimea's Muslim Tatars, generally seen as pro-Kiev, fled the southern peninsula after Russia annexed the province.
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