LONDON, March 27 (Xinhua) -- Firefighters and rescue crews were kept away from the scene of the Manchester Islamist terror attack for two hours, an official report into the May 22, 2017 bombing of Manchester Arena revealed Tuesday.

Additionally, the report said there had been confusion over whether a gunman was on the loose after the bombing at the close of a concert by U.S. pop singer Ariana Grande. Suicide bomber Salman Abedi detonated an explosive device, killing 22 people. Hundreds more were injured in the blast.

The report said the fire service was left effectively out of the loop of police and ambulance crews, so firefighters trained in first-aid and terror scenarios were not given permission to go to the scene, despite being stationed less than a kilometer away from the arena. Firefighters heard the bomb explode from their fire station, but were turned away from the scene, said the report.

The 226-page report by Lord Bob Kerslake was commissioned by Manchester Mayor Andy Burnham to assess the preparedness and emergency response to the attack last year.

The report said firefighters would have been much better placed to support and, potentially, to accelerate the evacuation of casualties if they had gone to the scene.

It added that the police duty inspector in the Greater Manchester Police force control room declared a pre-arranged plan when it was suspected an armed terrorist may be on the loose, and wrongly assumed other agencies were aware.

But the office was praised for taking one of the most crucial life or death decisions of the night -- a overriding the rules. This allowed paramedics and police to continue treating the injured even though they may have been in danger of further attacks.

A senior Greater Manchester Fire and Rescue Service officer stuck to rules, keeping emergency responders 500 meters away from any suspected zone of danger.

The report concluded that poor communication between the police and fire service meant fire crews only arrived two hours and six minutes after the bombing. Usually, its average response time is under six minutes.

Lord Kerslake said the unspeakable attack had been a brutal and real-world test of the emergency services' response.

He said there had been hundreds and thousands of acts of individual bravery on the night, adding: "not one single reason or one individual was to blame for the errors, but a most unfortunate combination of poor communications and poor procedures."

Kerslake said it was vital to learn lessons from what did not go so well.