MADISON, Wis. -

Police have issued protesters in the Wisconsin Capitol another round of citations.

Protesters have been singing songs complaining about Republican Gov. Scott Walker and GOP policies in the rotunda almost every noon hour for more than two years. Police launched a crackdown on them on July 24 for lacking a permit, handcuffing them, leading them off to their basement headquarters and citing them before releasing them.

They've issued more than 160 citations. They issued another 23 no-permit citations as well as a disorderly conduct citation on Tuesday.

State Sen. Jon Erpenbach, a Middleton Democrat, sent a letter to Capitol Police Chief Steve Erwin asking why officers handcuff and detain protesters for municipal no-permit violations. A state Department of Administration spokeswoman says Capitol Police are following standard police protocol.