NAIROBI (Reuters) - At least 33 people died in the Kenyan capital Nairobi during a police crackdown on opposition supporters after elections in August, including a child and a pregnant woman, Amnesty International and Human Rights Watch said on Monday.

Slideshow ( 8 images )

Protests erupted after President Uhuru Kenyatta was declared winner over opposition leader Raila Odinga in the vote. The Supreme Court later voided the result. Odinga has withdrawn from a re-run on Oct. 26, leaving Kenyatta as the only candidate, prompting further protests.

Kenyan police disputed the rights groups’ report, which brings the nationwide death toll in the crackdown to at least 45. Human Rights Watch had earlier documented 12 killings after the vote by police in western Kenya, the main opposition stronghold.

HRW and Amnesty said police in Nairobi had used “excessive force” and that “most of (the 33 who died) were killed as a result of action by the police.”

Among them was a nine-year-old child shot dead while standing on a balcony and a woman who was eight months pregnant and was trampled to death after fainting from inhaling tear gas, the rights groups said in the report.

Kenya’s National Police Service said in a statement the report was “totally misleading and based on falsehoods.”

Immediately after the violence in August, police said only “criminals” and “thugs” had been killed or injured.

The report is likely to bolster the case of Kenyan activists and rights groups who accuse police of brutality and extrajudicial killings but say few officers are charged and convictions are extremely rare.

“Researchers found that although police behaved appropriately in some instances, in many others they shot or beat protesters to death,” the groups said in the report.

On Thursday the government banned demonstrations in the central business district of Nairobi, the coastal city of Mombasa and the western city of Kisumu, where protesters had been gathering twice a week, calling on the election board to make reforms to ensure a fair poll. Police had used tear gas to disperse them.[L8N1MO1O3]

A group of U.N. human rights experts called for the government’s ban on protests to be listed and denounced a “pattern of police brutality” in response to recent demonstrations.

During the violence the parents of a six-month-old baby in western Kenya told Reuters their child was clubbed by police in her home and died later in hospital from brain trauma.

Kenya receives financial support for security from the United States, Britain and other international donors.