West African envoys who are in Monrovia to press President Charles Taylor to leave the country have been told he is not in the city.
Monrovia's civilians want peacekeeping troops to arrive soon
The envoys from the regional grouping Ecowas said they had informed the president in advance about their visit and were determined to stay overnight in order to see President Taylor on Saturday.
Hours before the delegation arrived, renewed fighting broke out in Monrovia, with at least nine people, including four children, killed by shelling near one of two key bridges leading to the city centre.
The United Nations Security Council is meanwhile meeting in New York to discuss a US draft resolution authorising the deployment of a multinational peacekeeping force into Liberia.
Exchanges of fire
"President Taylor is in [the southern port of] Buchanan because there is fighting going on there, that's the information we have," said Ghana's foreign minister Addo Akudo Addo.
But the BBC's Paul Welsh in Monrovia says it is not clear whether Mr Taylor is indeed absent or if he is just refusing to meet the delegation.
There are many people in the city who believe the president is actually still in his house, not far from where the ministers are now spending the night, our correspondent says.
The Ecowas envoys, including the group's Mohammed ibn Chambas and three ministers, want Mr Taylor to leave, as promised, three days after 1,500 Nigerian troops arrive on Monday - the first contingent of a West African force.
Monrovia had been relatively calm since a Nigerian-led military fact-finding team arrived on Wednesday night.
But on Friday, several shells landed in the diplomatic area of Mamba Point and rebels and government fighters exchanged fire around the two key bridges.
The BBC's Barnaby Philips in Monrovia says crowds of people who had emerged from shelter to seek water, food and medicine ran for cover as the shells landed.
The total force of 3,250 peacekeeping soldiers is expected to deploy within three weeks.
Monrovia residents have welcomed the announcement that Ecowas troops were on their way.
"Most of us are tired of war. We want a reunion with our people. Every Liberian wants to interact with his family," one Monrovian told Reuters news agency.
The main rebel group - Liberian United for Reconciliation and Democracy (Lurd) - on Friday renewed their call for the Liberian president to honour his promise to stand down.
"Mr Taylor must go. Mr Taylor cannot be a positive factor in any new dispensation in Liberia," Kabineh Janeh, who heads the Lurd delegation at the Accra peace talks told the BBC's World Today programme.
Nigeria has offered asylum to Mr Taylor - who faces war crimes charges in the United Nations-backed tribunal for Sierra Leone.
Mr Chambas has indicated that Mr Taylor is unlikely to be tried soon.
"He is not going to Sierra Leone, he is going to Nigeria," Mr Chambas told the BBC.
Liberian minister Samuel Jackson said that Mr Taylor wanted a formal handover of power, preferably to his Vice-President Moses Blah.
Ecowas announced on 4 July it would send the mainly Nigerian troops to Liberia but the deployment has been hampered by continuing fighting and haggling over who will bear the cost of the mission.
Washington repeated on Thursday that it would back the West African peacekeeping effort.
The US had "put up $10m that will go in the form of a contract for logistics support," State Department spokesman Richard Boucher said.
Conditions in Monrovia are said to be appalling, with increasing numbers of children facing malnourishment as food and water supplies run dangerously low.
International aid groups say they can do little to help the 1.3 million people trapped in the city.
"We have stocks, and our problem is that we just cannot... distribute them to the needy population," Gregory Blamoh, head of the World Food Programme mission in Monrovia, told the BBC.
"To be able to distribute this food there had to be cessation to the current fighting," he added.
Rebels control the capital's food stocks in the port area and have been accused by the government of looting - though they say they have simply been handing out food to the hungry.
Another rebel group captured Liberia's second city, Buchanan, earlier this week, cutting off the last remaining route for food imports to get to government-held parts of the capital.