PORTLAND, Maine — Federal immigration officials have ceased their “enhanced operations” in Maine, the site of an enforcement surge and hundreds of arrests since last week, U.S. Sen. Susan Collins said Thursday. Collins, a Republican, announced the development after saying she had spoken directly with Secretary of Homeland Security Kristi Noem. “There are currently no ongoing or planned large-scale ICE operations here,” Collins said in a statement, referring to U.S. Immigration and Customs Enforcement. “ICE operations in Maine have failed to improve public safety and have caused lasting damage to our communities. ICE has also launched immigration operations in Minnesota, Chicago and other cities.