Federal agents knock on a door in Lewiston on Jan. 21. (Russ Dillingham/Staff Photographer)U.S. Immigration and Customs Enforcement said Thursday that it arrested 206 people in Maine last week, the first week of an enhanced immigration operation that Sen. Susan Collins says has since ended. In a news release Thursday, the federal agency criticized Maine residents and local politicians for attempting to “thwart” agents’ activities while touting the apprehensions as an overall success. “ICE will not be deterred from enforcing U.S. immigration law.”ICE also blamed people for interrupting agents’ work during the first week of the operation. “On a few occasions, ICE officers were forced to pull away from criminal alien targets because of activists alerting the public to unmarked ICE vehicles.