MINNEAPOLIS — Hennepin County sheriff’s deputies have left the front lines of the Dakota Access pipeline protest in North Dakota and are headed back to the Twin Cities, where hundreds of people last week called for the withdrawal.

Sheriff Rich Stanek said30 of his deputies have fulfilled their duties under the Emergency Management Assistance Compact, a national system for sharing personnel during a state of emergency.

Hundreds of people have been protesting in southern North Dakota for months, supporting the Standing Rock Sioux tribe’s opposition to the $3.8 billion pipeline from North Dakota to Illinois. Officers from several states have been helping North Dakota authorities with the response.

Some, including Lt. Gov. Tina Smith, think Minnesota’s aid wasn’t called for. State Rep. Tony Cornish accused Smith of playing politics.