GENEVA (Reuters) - The United Nations human rights office and refugee agency UNHCR urged Jordan on Tuesday to open its border to Syrians trying to escape an escalating conflict in the southwest region of Deraa.

An estimated 270,000 people have fled air and ground attacks over the past two weeks, the United Nations said on Monday

“We call on the Jordanian government to keep its border open and for other countries in the region to step up and receive the fleeing civilians,” U.N. human rights spokeswoman Liz Throssell told a news briefing.

UNHCR spokesman Andre Mahecic said an estimated 40,000 Syrians were massed near the border with Jordan, which already hosts 650,000 registered Syrian refugees.