A prominent human rights group is demanding Kenya hold its security forces to account for rampant abuses against refugees.

Human Rights Watch accused Kenyan forces of targeting ethnic Somalis and Kenyans in Kenya's North Eastern province during a six-month period starting last November. The group's report, issued Friday, said the abuses were part of a campaign of retaliation for a series of attacks on Kenyan soldiers by Islamist al-Shabaab militants and their supporters.

The 65-page report said the abuses included rape, attempted sexual assaults, arbitrary detentions, extortion, looting and beatings. It says the most serious allegations come from the Dadaab refugee camps, which house more the 460,000 refugees.

The report says in some cases, Kenyan security forces beat children as young as 4.

Human Rights Watch says the Kenyan government has promised to investigate the alleged abuses but that, so far, no one has been held accountable.

The Associated Press said Friday the Kenyan Police Commissioner Mathew Iteere promised to investigate the allegations.

Kenyan troops entered Somalia as part of the African Union Mission in Somalia's effort to help prop up the country's weak transitional government, which is battling al-Shabab. HRW says the alleged Kenyan police abuses against Somalis has created an atmosphere of mistrust around their mission in Somalia.