The British government says it is to pay for charter ships to aid the evacuation of 5000 migrant workers who are stranded in the besieged Libyan city of Misrata.
International Development Secretary Andrew Mitchell has pledged funds of 1.7 million euros.
The International Organisation for Migration has already organised two boat-loads of people to take to Benghazi.
Many passengers, who included war casualties, were desperately sick.
Dramatic new images show Libyan rebels in Misrata defending themselves against bombardment from Colonel Gaddafi’s forces.
For seven weeks they have been keeping at bay government troops surrounding Libya’s third largest city.
A rebel spokesman said 17 people were killed in Sunday’s shelling.
A US-based human rights group accuses government forces of launching indiscriminate attacks on residential areas.
One rebel commander said they tried in vain to get NATO to intervene. Ten times over the past month they called to give co-ordinates, he said, but received no reply.
Conditions in Misrata are described as dire, with shortages of food, medicine, water and power. The only route out is by sea.
Meanwhile diplomatic efforts continue to try to stop the fighting and obtain humanitarian access for the city’s people.
Valerie Amos, the UN’s Deputy Secretary General, spoke from Benghazi after failing in Tripoli to get the bombardment of Misrata to stop.
“I’m extremely worried about the situation there, I very much hope that the security situation will allow us to get into Misrata. Nobody has any sense of the depth and scale of what is happening there,” she said.