GENEVA (Reuters) - Syrian banks are reported to be running out of cash and a rush to find safe housing has caused rents in some places to spike to $100 per night, the U.N. refugee agency UNHCR said on Friday.

"We've heard reports that many of the banks have just run out of money," UNHCR's chief spokeswoman Melissa Fleming told a U.N. briefing in Geneva.

"I just have a report from our staff that says state and private banks are reported to be out of funds. Whether this is all banks, I don't know," she said.

"This is specifically relevant to the refugee population as reported but it's probably also affecting the Syrian population."