A human rights group says Kenyan security forces have carried out beatings and arbitrary detentions near the Somali border.

New York-based Human Rights Watch released a report Thursday, a day after it says security forces rounded up and beat civilians in the eastern town of Garissa.

The report describes a series of abuses mostly targeting ethnic Somalis. The incidents took place after Kenyan forces entered Somalia in October to push back al-Shabab, a militant group Kenya blames for a series of cross-border kidnappings.

Human Rights Watch says the worst abuses took place at the Dadaab refugee camp, which is home to more than 400,000 Somali refugees. It says police responded to attacks against security forces there in December by beating refugees, carrying out arbitrary arrests and raping women.

The report says the Kenyan military pledged to investigate the group's allegations.