We don't want to point at anybody but we want the government to stop these human rights violations

MP Beth Mugo

But in an interview with the BBC, police spokeman Peter Kimathi said the allegations were untrue, and no evidence of rapes had been presented to them.

At least seven people were killed and an estimated 3,000 people fled Kibera - Kenya's largest slum, home to 500,000.

The BBC's Muliro Telewa in Nairobi says tension heightened in the area following a speech by President Daniel arap Moi in October.

Mr Moi had said that the landlords should reduce the rent since they did not legally own the land.

Not named

The chairperson of Kenya's women parliamentarians, Beth Mugo, introduced a parliamentary motion on the alleged mass rape.

None of the alleged victims were named. "In this room, some women were sexually molested but we don't want them to talk without making sure that they will be protected," she later told a news conference.

The fighting took on an ethnic dimension

"We don't want to point at anybody but we want the government to stop these human rights violations, these women's and children's rights violations," she said.

On Tuesday, several people were hacked to death with machetes and a number of houses were torched before police intervened with live ammunition and tear-gas to break up the disturbances.

Reports of the number of people killed range from seven to 12. Police spokesman Peter Kimanthi said 33 people were wounded and 57 arrested.

Political rent

The fighting followed Monday's visit by local MP, Raila Odinga, an ethnic Luo.

"The government is the true landlord, the landlords are the tenants and tenants are the subtenants ... the government will tell the landlords to lower the rent," he told the thousands who had gathered to hear him.

This place is a slum, why should anyone pay to live here

Irene Ochanda Luo tenant

But Mr Odinga has denied he is stoking ethnic tension ahead of elections next year. The Nubians were settled in the Nairobi region during the colonial era but have never been given title deeds to the land.

"We built these houses to make a living, to help us earn money," said Adbullah Ali, an unemployed 32-year-old Nubian. "Now we are just protecting our properties... the government cannot come here and tell us to stop earning money."

There is little running water and poor sanitary facilities.

Irene Ochanda, an ethnic Luo whose Nubian-owned lodgings were burnt down by a gang of Luos on Tuesday agreed with Mr Odinga.

"This place is a slum, why should anyone pay to live here," she said.