Up to 30,000 Syrian refugees may have crossed into Lebanon in the past 48 hours, in what would be a sharp increase of people fleeing fighting in the country, the United Nations refugee agency UNHCR said on Friday, July 20.

Syria's borders remain open, it said, but the agency was not able to confirm reports Syrian rebels took control of two major crossings on the border with Turkey and the main Abu Kamal post on the border with Iraq on Thursday.

"We have reports we are trying to verify that thousands of Syrians overnight and yesterday crossed into Lebanon. So far reports vary between 8,500 and 30,000 people who may have crossed in the past 48 hours," Melissa Fleming, chief spokeswoman of the U.N. High Commissioner for Refugees (UNHCR), told a news briefing in Geneva.

"Borders remain open. People continue to arrive in Turkey. People continue to arrive in Jordan. People continue to flood into Lebanon and increasingly into Iraq," she said, Reuters reported.