The FBI on Thursday announced a major expansion at Redstone Arsenal as it plans to bring hundreds of jobs to the Army base in Huntsville.

The agency, which already has a significant presence at Redstone, is relocating 1,350 employees from locations in and near Washington, according to Robert Hamilton, senior executive, FBI Redstone Arsenal.

Huntsville Mayor Tommy Battle told AL.com on Thursday that the new jobs are part of an anticipated FBI expansion on the arsenal that will ultimately reach between 4,000 and 5,000 jobs.

“The FBI is extremely excited to announce today that we are moving forward with our first large-scale operations support building,” Hamilton said during a presentation to business and community leaders at the annual Redstone Update. “We expect that to be ready for occupancy in early 2021. This will move approximately 1,350 personnel and contractors from the national capital region.

“This building will accommodate a cross-section of FBI employees to include special agents, intelligence analysts and professional staff. And we will house a number of operations support divisions that play a critical role in supporting the FBI mission of protecting the American people.”

The FBI currently has approximately 300 employees at work on its two Redstone Arsenal campuses – a 243-acre plot that can expand to 400 acres on its north campus in the professional district of the arsenal as well as 1,200 acres on its south campus, which is home to the FBI’s Hazardous Devices School.

“This is not a relocation of resources but rather a transformation of mission sets to one extremely powerful campus,” Hamilton said of ongoing and future FBI operations at Redstone Arsenal.

The FBI announced in February that it would be shifting about 2,500 jobs across four states from its Washington headquarters. It’s not immediately clear if the Huntsville jobs announcement on Thursday was a part of that 2,500.

Hamilton declined to comment further on the Huntsville jobs following his presentation.

For Battle, the jobs announcement had been expected but he still wore an ear-to-ear smile on his face Thursday. The mayor also focused on the presentation by John Underwood, special agent in charge for Alcohol, Tobacco and Firearms.

Battle also said that while about 43,000 people work at the arsenal, that number could grow to more than 50,000.

“What you’re also hearing (in addition to the FBI jobs) is that people are being brought in for training,” Battle said. "You hear the ATF said it brought 4,000 people (to Redstone) for training last year, those 4,000 people stayed here for an average of three or four days, they filled up the hotels, they ate at the restaurants. It just added more to your economy.

“We’ve got both ATF and FBI doing that and numerous other agencies who are bringing people in and they become part of our economy, also.”

Hamilton also announced that the FBI will complete construction of its ballistics research facility at Redstone Arsenal in the spring of 2019.

“The entire capability will be relocated from Quantico to Redstone Arsenal as part of the FBI’s portfolio,” Hamilton said.

And the last of a four-phase project will begin early next year to bring the complete TEDAC capability to Redstone, Hamilton said. The facility was first opened on the arsenal in 2016 when former FBI Director James Comey visited Huntsville.

And as Comey hinted – at the urging of Alabama Sen. Richard Shelby – at that ribbon-cutting, Hamilton said Thursday that part of the FBI’s headquarters has already relocated to Redstone Arsenal and is working in temporary spaces.

Updated today, Nov. 29, 2018, at 2:01 p.m. with new information throughout.