RIVERSIDE, Calif. (AP) - Immigrant rights advocates in Riverside want the Department of Homeland Security to investigate a series of arrests by Border Patrol agents made under what they called "vigilante-style" conditions.

Advocates said Thursday they will send a letter to Homeland Security Secretary Janet Napolitano to request a probe of arrest practices by Riverside agents over the last nine months.

Advocates have questioned dozens of arrests, including an incident last month when an agent pulled a man's wallet from his pocket and arrested him when he refused to speak.

The Riverside station has faced scrutiny in recent months after agents complained they were assigned arrest quotas.

Border Patrol management said agents were not forced to meet quotas and ordered an internal probe in February. No results have been made public.