KAMPALA, Uganda — Homeless children in Uganda's urban centers face beatings and abuse at the hands of police and local officials, Human Rights Watch charged in a new report that urges Ugandan authorities to protect street children from targeted roundups and arbitrary detentions. A police spokesman said the allegations are "totally not true."Street children have long been ubiquitous on the streets of the Ugandan capital, Kampala, where they risk being knocked down by speeding cars as they beg motorists for money. Many of the children are young girls with babies on their backs, one reason why it is widely believed they are sexually assaulted while on the streets.Law enforcement officials in Kampala conduct random operations to rid the city of street children who put on trucks in order to be sent back to their original homes, often in the arid, poor parts of northeastern Uganda.The Uganda government has failed to protect homeless children from abuse by police, local officials, and even homeless adults who may force them to take drugs, said Human Rights Watch in a new report released Thursday, condemning what it called "targeted roundups" of street children.Both boys and girls have been sexually assaulted or raped, alleged the report. They face violence and forced labor in police cells, where they are beaten with "batons, whips, or wires to extort bribes or as a punishment for vagrancy," according to Human Rights Watch."Ugandan authorities should be protecting and helping homeless children, not beating them up or throwing them in police jails with adults," said Maria Burnett, senior Africa researcher at Human Rights Watch. "The government should end arbitrary roundups of street children and protect them from abuse."The allegations are "quite alarming but totally not true," said Patrick Onyango, a spokesman for police in Kampala. He said only "violent and wild" children below 18 are arrested and taken to remand homes for juveniles."We don't keep children in our cells. If you're below 18 you can't be in our cells," he said.Local watchdog groups say that, while they are not opposed to the removal of street children, the methods used are questionable and lack proper guidelines.Marlon Agaba, a spokesman in Uganda for the children's rights advocacy group ANPPCAN, said authorities in Kampala have been known to use "inhumane methods" while removing homeless children from the streets."There is no strategy, no policy for withdrawal, rehabilitation and integration of these kids back into their communities," he said. "Because these children are forced on the street by circumstances."