The United Nations has appealed for a ceasefire in the Libyan city of Misrata, saying at least 20 children had been killed in attacks by government forces.
Hundreds of people are believed to have been killed by shelling and sniper fire from Muammar Gaddafi's forces in the city.
Misrata is the main focus of efforts to protect civilians caught up in the Libyan leader's attempt to put down an armed rebellion.
Marixie Mercado of UNICEF said: '50 days into the fighting in Misrata, the full picture of the toll on children is emerging.
'It is far worse than we had feared and certain to get worse unless there is a ceasefire.
'We have at least 20 verified child deaths and many more injuries due to shrapnel from mortars and tanks and bullet wounds.'
Aid groups say food, medicines and other basic items are in short supply in the city.
Tens of thousands of casualties and foreign workers are waiting at the port to be rescued.
Western powers are looking for ways to support the rebels in their efforts to topple Gaddafi.
Britain said it would send military officers to advise the rebels on organisation and communications, but not train or arm fighters.
Italy said the international Libya Contact Group was seeking ways to allow the rebels to sell oil produced in the rebel-held east despite a UN embargo on Libyan oil sales.
A NATO-led air campaign designed to keep Gaddafi's forces out of the air and prevent attacks on civilians has failed to halt the bombardment of Misrata.
French Prime Minister Francois Fillon has said his air force will step up its air strikes in Libya to protect civilians from Gaddafi's forces.
Mr Fillon said: 'We will intensify our military effort from our air force to prevent Gaddafi forces from pursuing their attacks on civilian populations.
'But at the same time, we will need to find a political solution, that is conditions for a dialogue so that the Libyan crisis can be resolved.'
