GENEVA (AFP) - The UN refugee agency said on Tuesday that it had boosted security in Yemen, as Western nations shut their embassies there following a worldwide terror alert issued by the United States.
"We're there, but we're operating under extreme caution, and certain restrictions," Ms Melissa Fleming, spokesman for the United Nations High Commissioner for Refugees (UNHCR) told reporters, without giving details.
It was not clear what measures other UN aid agencies may have taken in the face of fears of an attack.
The UN's Geneva spokesman Corinne Momal-Vanian said the world body did not comment on its security steps.
Washington closed some two dozen embassies and consulates on Sunday, many of them in Muslim nations, warning of an Al-Qaeda attack, and a string of Western countries followed suit.
The United States also ordered Americans to leave Yemen immediately and withdrew all non-essential US government staff.
The alert was reportedly linked to the interception of communications between Al-Qaeda leader Ayman al-Zawahiri and the leader of the group's Yemen-based affiliate.
UNHCR operations in Yemen focus on helping the hundreds of thousands of people, mostly from the troubled Horn of Africa, who cross there in the hope of reaching wealthy Gulf states.
Many of those who survive the perilous Red Sea crossing at the hands of people-smugglers end up stuck in communities near the tightly-controlled border between Yemen and Saudi Arabia.
More than 46,000 people have arrived in Yemen in the first six months of this year, mostly from Ethiopia, Ms Fleming said.
Last year, a record 107,500 people made the journey.