The US called on Liberian rebels to withdraw from the capital today as fighters edged forward against President Charles Taylor's forces and mortars continued to terrorise Monrovia's war-weary people.
A top West African official said Nigerian troops would be deployed to the battered country this week but it remained unclear whether US troops would be deployed on the ground.
Residents said the rebels had advanced well beyond the key Stockton Creek bridge where fighting has been concentrated since the latest rebel assault, the third in less than two months.
The bridge puts them on a road that cuts around the swamps behind central Monrovia and towards a vital junction to the main airport and Taylor's residence.
The US embassy urged rebels to withdraw. US ambassador Mr John Blaney told reporters the Liberian government had accepted a US proposal to use the Po River - which lies 12 from Monrovia's outskirts - as a new demarcation line.
Mr Blaney urged the rebel Liberians United Reconciliation and Democracy (LURD) to do the same. The LURD pushed into a suburb known as New Georgia today, residents in hiding said, adding they could hear the continuous blast of heavy weapons.
"Many innocent people are dying. Water is scarce and food is running low. Disease is out of control. If LURD has regard for the people of Liberia, it will accept this proposal," he said.
"This natural boundary (the Po River) will help verification and monitoring personnel as well as peacekeepers coming to Liberia to secure and rebuild the ceasefire," Mr Blaney said.
Aid workers said more mortars landed overnight close to a church where seven people were killed yesterday. They said at least 20 people had been seriously wounded but it was not immediately clear if anybody was killed.
Residents said four mortar bombs had also dropped around Mechline street, in the centre of the city, wounding four.