Counter Terrorism Policing North East tested police, firefighter and paramedics during a pre-planned operation at various locations in Wakefield and Calderdale.
They included a 12-hour exercise at Ferrybridge Power Station on Wednesday which involved staged explosions and simulated gun fire.
The scenario saw first responders from the emergency services deal with a marauding terrorist firearms attack and resolve a siege situation involving a large number of hostages.
Teams from regional police forces, West Yorkshire Fire Service and Yorkshire Ambulance Service were tasked with detaining the suspects, managing the scene, protecting the public and rescuing the wounded.
Detective Superintendent Matt Davison, regional co-ordinator for Protect and Prepare at the Counter Terrorism Policing North East, said: "Exercises such as this are an important opportunity for us to test our skills and tactics and ensure that our multi-agency plans are as effective as they can be in managing incidents and keeping the public safe.
"It’s vital we train together for incidents of this nature and learn as much as possible from the range of challenges they present. All partners are fully committed to ensuring we are thoroughly prepared should the worst happen in our area."
The sessions in West Yorkshire were among a number of national counter terrorism exercises which routinely take place throughout the UK under the Government’s rolling programme.
Such exercises now form part of the legal obligation of the emergency services and partner agencies to prepare and practice for major incidents under the Civil Contingencies Act.
Letters had been sent to residents living near to the chosen locations in advance so that they did not panic if they heard the explosions or gun fire.
Det Supt Davison said: "The noise from small pockets of exercise activity may have been heard locally. However, we made every effort to keep disruption to a minimum and there was absolutely no risk to the public at any time. Neither was there any impact on the front line services of the police or our regional emergency partners, which continued as normal.
"We’re grateful for the patience and cooperation of local people and for the support we’ve received from SSE and Together Housing who assisted us in hosting this exercise. We’re really pleased with the dedicated and professional response to the incident by those taking part."
He said a full debrief of the exercise would now take place to ensure lessons learned were added into major incident plans.
Nick Hinde, SSE’s site manager at Ferrybridge, said they had always had a close working relationship with the emergency services.
"We are pleased that we were able to help facilitate this exercise at the Ferrybridge site," he said.
"We would like to thank everyone involved for the consideration that they showed towards our neighbours in trying to keep disruption to a minimum, and for working so closely with our team at Ferrybridge to ensure that the exercise was carried out successfully and most importantly, safely.”
Caroline Grosvenor, head of sustainable communities at Together Housing Group, added: “We work hard to keep our communities safe and it’s important we also help our partners to prepare for all eventualities so it is an absolute privilege to be able to help our dedicated emergency services with this important exercise.”