|UN officials fear that many African migrant workers are trapped inside Libya [Reuters]
Andrew Mitchell, Britain's minister for international development, has said that migrants fleeing violence in Libya are in a "desperate position" and demanded that Libya allow world powers "unfettered access" to help them.
In an interview with Al Jazeera on Saturday, Mitchell blamed Muammar Gaddafi, the Libyan leader, for the plight of those fleeing and said that world powers should be prepared to act.
"The whole of the international community should recognise that there are people in a desperate position inside Libya thanks to the way Colonel Gaddafi is behaving and that the international community must make sure it is able to respond to every eventually," he said.
"We call immediately for unfettered access into Libya for the international community ... It has been cut off by Colonel Gaddafi and we call for it immediately to be reopened."
More than 191,000 people have fled the violence in Libya, according to a report by the UN's Office for the Co-ordination of Humanitarian Affairs (OCHA), citing figures from the International Organisation for Migration.
About 3,500 Bangladeshi workers have returned home since the anti-government protests began, according to the OCHA, but tens of thousands of others remain stuck in Libya, where forces loyal to Gaddafi are suspected of preventing many from crossing the border.
People fleeing Libya for Tunisia said they had to pass through dozens of checkpoints on their way from Tripoli, the capital, and that they had been robbed by Gaddafi's security forces.
Some people who crossed into Tunisia in the last two days have reported seeing thousands of fellow migrant workers on the Libyan side, but UN officials said it was unclear why they were not approaching the border.
Speaking to Al Jazeera's David Frost, Antonio Guterres, the UN high commissioner for refugees, warned that many, mainly African, workers trapped in Libya were at risk.
Guterres said Gaddafi's use of African mercenaries had generated popular suspicion towards anyone from
"There are hundreds of thousands of African workers in Libya, and very few have shown up at the borders," he said.
"We have received phone calls from people in a desperate situation, afraid of leaving their homes. It's the situation of
these African communities inside Libya that now corresponds to our biggest concern."
Ban Ki-moon, the UN secretary general, is expected to name a special envoy to Libya in coming days. Abdul-llah Khatib and Marwan Muasher, both Jordanian diplomats, are said to be under consideration for the post.
Tunisia is readying for an influx of hundreds more people fleeing the unrest in the coming days.
Algeria and Egypt, as well as France and Italy, have also all mobilised to receive and repatriate refugees.
In Algeria authorities said they were reinforcing their reception capacity for refugees from Libya with a new facility at Ifri, about 2,000km southeast of Algiers.
A humanitarian convoy left Tabessa in the far east of Algeria for the border between Libya and Tunisia to help refugees, the Algerian news agency APS said.
Also on Saturday, an Italian navy patrol boat set out for Libya on Saturday with a cargo of aid, as part of a humanitarian mission, the Italian defence ministry said.
The "Libra" carried tents, 4,000 blankets, water purification kits, power units and first aid kits to Benghazi, the second largest city in Libya and a stronghold for anti-government fighters.
Before the uprising in Libya there were 2.5 million migrant workers in the country, including one million Egyptians, migration officials say.
Most were in the eastern city of Benghazi, which is held by the rebels.