The United Nations observed the annual International Day Against Torture Wednesday, as human rights groups in Kenya alleged that the country's police routinely use torture against people charged with crimes. Kenyan police vigorously deny the allegations.

A U.N. special report investigating torture in Kenya two years ago charged that the practice was both systematic and widespread.

Kenyan authorities say they have taken firm steps to root out torture from the country's police stations and jails. Police spokesman Peter Kimanthi said there are few cases of torture now because law enforcement officers are heeding their commissioner's warning that torture will not be tolerated.

"Any police person who is [found] to be torturing suspects or mishandling members of the public is dealt with according to the law," he said. "We arrest, and charge them in court and deal with them disciplinarily and dismiss them in most cases. So, torture is not something acceptable within the police force, not only within the force but elsewhere in the country."

But human rights groups say the situation has not improved.

Ling Kituyi, the head of a nationwide group of doctors and lawyers who investigate possible torture incidents and provide evidence to the courts, said there are at least 500 cases of torture each year in Kenya. She said proving the charges in court is often difficult.

"We need an independent prosecution. Right now, the police are prosecuting themselves and again not willing to bring evidence available to the attention of the magistrate," she said. "We need to shorten the period in custody. What is happening now is that people are now charged with robbery with violence. There is a 14-day period before they have to appear before the magistrate. It is in that period that they are most at risk of torture. We would want people to be brought before the magistrate within 24 hours."

Dr. Kituyi charged that police often consider torture a quick and effective way to solve a crime by beating an accused person into signing a confession. She said torture also is used to extort money from those arrested or their families.

She said she has seen torture victims with bruises, whip marks, neurological damage including paralysis and blindness, and ruptured bladders.