Talks aimed at resolving Kenya's post-election crisis have resumed in the capital Nairobi.
Houses in western Kenya are still being torched
Scores of people have been killed in the last two days despite an agreement signed by President Mwai Kibaki and opposition leader Raila Odinga.
Mr Odinga called on Sunday for foreign peacekeepers, saying he does not trust national security forces.
Weeks of political and ethnic violence have left hundreds dead and driven many thousands from their homes.
Mr Kibaki claimed victory in the presidential vote on 27 December but the opposition says the vote was rigged.
The unrest has blocked many of Kenya's main road and rail links, which are vital for Uganda, South Sudan and the Great Lakes region.
A delegation of Ugandan ministers has travelled to Tanzania, to discuss importing goods via its port of Dar-es-Salaam, instead of Mombasa in Kenya.
South African role
Former UN chief Kofi Annan on Friday brokered a deal between Mr Kibaki and Mr Odinga, setting up a framework for the negotiations.
But the man he hoped would lead the talks, South African businessman Cyril Ramaphosa, has been dropped from the mediation panel, because of objections by the Kenyan government.
Mr Ramaphosa played a key role for the African National Congress negotiating with South Africa's last minority white government.
Meanwhile, the former Archbishop of Cape Town, Desmond Tutu, has appealed for an end to the "totally unacceptable" violence and called on Kenyans to back the talks.
"My heart aches for Kenya. Your countrymen and women have suffered greatly," he told the BBC.
"It is in your power to stop the violence if you act as one. You have an opportunity now to stand up for peace."
'At the brink'
The discussions are due to last a month and aim to halt the bloodshed within two weeks.
Hundreds of thousands of people have been forced to flee
The two sides are due to discuss the key allegations of electoral fraud this week.
Other issues that the two parties agreed to address are the humanitarian situation, the political crisis, and land and historical injustices.
But politicians have rapidly resumed their war of words.
A senior colleague of Mr Odinga, William Ruto, told the BBC that without foreign intervention there would be no peace.
"We are committed to ending this violence but it will not happen in a day or two or three or a week," he said.
"You should understand the situation in this country is that we are literally at the brink."
Mr Odinga called for peacekeepers from the UN or the African Union "because the police have often been misused and we do not have faith in the army to be neutral."
But Mr Kibaki and his supporters continue to accuse the opposition of fuelling the unrest.
"This is a politically instigated situation," said information minister Samuel Pergisio.
"It is a process that requires these politicians to go back and speak to their people."
Meanwhile, the violence has continued.
On Sunday, pitched battles between youths armed with bows, arrows, machetes and rocks were reported in the west of the country.
In Nyanza province, police trailed fighters after they razed more than 100 houses and a primary school, Reuters news agency reported.