The vote counting in Kenya's violently contested election was rigged, but it's unclear who is responsible, the chief U.S. envoy in the country said on Monday.

Jendayi Frazer declined to blame either President Mwai Kibaki or opposition leader Raila Odinga for rigging the election, saying they both could be to blame.

"Yes, there was rigging," Frazer told The Associated Press. "I mean there were problems with the vote counting process ... both the parties could have rigged."

Earlier Monday, Frazer told reporters that Kenyans "have been cheated by their political leadership and their institutions." The election has been described as deeply flawed by international observers.

The contested election sparked political and ethnic violence that has caused nearly 500 deaths after Kibaki was issued a slim victory.

Frazer has spent the last three days negotiating a truce between the two leaders with some apparent success.

On Monday, Kibaki invited Odinga to his home in order to discuss how to end the deadly feuding.

Odinga had earlier cancelled demonstrations in an attempt to avoid more bloodshed. He made the announcement to cancel the protests, scheduled for Tuesday, after a meeting with Frazer.

African Union Chairman John Kufuor, Ghana's president, is expected to arrive in Nairobi on Tuesday to meet with both parties. His visit had been delayed several times due to refusals from Kibaki's government to accept outside mediation.

"We are now sure that mediation will start," Odinga told reporters on Monday. "We have consulted and decided that the public rallies we called for are cancelled. We want the mediation to take place in a peaceful environment."

Both Odinga and Kibaki have said they are willing to enter into some sort of power sharing agreement, although Odinga said the agreement would have to be guaranteed by the international community.

Feuding leaves hundreds dead

The political divide has split Kibaki and Odinga's supporters largely along ethnic lines with Kibaki's backers -- mostly members of the Kikuyu people -- pitted against Kenya's other tribes.

An official statement on Monday said 486 people have been killed and some 255,000 have been displaced in the fighting.

On Monday, 30 more Kenyan refugees were presumed dead after being thrown into a river near the Ugandan border.

A Ugandan official confirmed that two truck drivers shuttling the refugees -- identified as members of Kibaki's Kikuyu tribe -- were stopped by a militia, who forced them into the Kipkaren River.

Aid organizations across the country were trying to help thousands of homeless and hungry Kenyans meet basic necessities.

Canadian Ralph Bromley, president of the Canadian relief agency Hope for the Nations, said aid isn't getting to people from the UN or the Kenyan government, leaving his organization short on supplies and money.

"There is a desperate need for food. And they cannot wait for, you know, three weeks, four weeks for containers," Bromley told Canada AM from a refugee camp in Bungoma, Kenya on Monday.

Bromley said violence has stopped for now, but Kenyans fear it could spark up at any time.

"We have seen in past days many burned vehicles, burned homes, burned businesses, and right now, there's a very eerie calm," he said.

Political fallout

The cancellation of protests marks a vast change in Odinga's stance from just days ago, when he refused to discuss to possibility of a coalition government with Kibaki.

He said Kibaki was elected fraudulently and had no power to negotiate. Late Sunday, he agreed to discuss the possibility of power sharing.

Odinga has suggested an interim government be set up to hold new presidential elections, but Kibaki has said only a court could order a new election.

The current government will have trouble ruling without the opposition's support. Odinga's party holds 95 of the 210 seats in the legislature.

Kibaki's government has called for parliament to meet for its first session on Jan. 15.

With files from The Associated Press