Spectators can expect few changes to the security plan for the Boston Marathon this year, law enforcement officials said Wednesday.

Thousands of uniformed and plainclothes officers will patrol the 26.2 mile route — an operation that also includes K-9 units and dozens of security cameras, officials said.

The plan is as rigorous as it has been in the years since the 2013 Marathon bombings, said Daniel Bennett, secretary of the state’s Executive Office of Public Safety and Security.

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“It hasn’t dropped off one iota in the last couple of years,” Bennett said at a morning press conference. “No one has stopped doing that work. It hasn’t faded in anybody’s memory, that terrible day.”

Spectators have been advised not to walk out onto the race route, and to leave backpacks and coolers at home. Any bags used to carry items should be see-through, officials said.

The length of the Marathon route has also been deemed a “no drone zone,” officials said.

The law enforcement community has been on especially high alert to the threat of terror and recent attacks in Brussels, Paris and San Bernardino, but there are no credible threats to the marathon this year, FBI Special Agent in Charge Hank Shaw said.

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“Neither the FBI, nor our intelligence community partners has any information which indicates an interest or active threat directed at this marathon,” Shaw said.

Multiple state, local and federal law enforcement organizations are collaborating to oversee the race via a joint intelligence center, officials said.

Spectators were asked to report suspicious activity by alerting a nearby police officer or calling 911.

“In short, the runners and the members of the public who come out to cheer them on and celebrate this great Massachusetts day should be assured that security of the race route is our priority,” said State Police Col. Richard McKeon.

The race begins April 18 in Hopkinton.

What not to bring:

  • weapons (including firearms, knives and mace)
  • backpacks
  • suitcases and rolling bags
  • coolers
  • glass containers or cans
  • flammable liquids, fuels, fireworks or explosives
  • any container capable of carrying more than 1 liter of liquid
  • bulky items larger than 12 inches by 12 inches by 6 inches
  • large blankets or sleeping bags
  • costumes covering the face or “nonform fitting, bulky outfits extending beyond the perimeter of the body”
  • props (including sports equipment)
  • drones
  • poles

Learn more at the Boston Athletic Association’s website.