Noel Phillips was reporting from Minneapolis, where violent protests have broken out over the fatal shooting of a black man by police.
Daunte Wright was killed on Sunday during a traffic stop in the suburb of Brooklyn Center.
A police officer has claimed she accidentally shot him after mistaking her gun for her taser.
In his broadcast, Phillips describes a 'growing crisis' and 'a very tense standoff between protesters and police' before gunshots can be heard in the background.
A Good Morning Britain reporter was forced to run for cover in Minnesota after his segment was interrupted by gunshots
The reporter looks around nervously before shouting begins and a man can be heard saying 'Get out now!' as the crew begin to run.
'We heard 20 to 30 gunshots fired from a group of men towards the police,' Phillips said.
Later in the programme, the journalist revealed he was wearing 'body armour' during filming as he believed the situation could become dangerous.
'We saw gunshots being fired, and as a precaution while doing this job we tend to wear body armour to protect ourselves,' he said, revealing a bulletproof vest underneath his jacket.
Noel Phillips was reporting from Minneapolis, where violent protests have broken out over the fatal shooting of a black man by police, when he heard gunshots
The crew was forced to run for cover after hearing what Phillips said were '20 to 30 gunshots'
Hundreds of protesters took to the streets of Brooklyn Center for a second night on Monday, defying a curfew imposed by the mayor, and gathered outside the police headquarters.
Police shot tear gas and stun grenades at protesters in an attempt to disperse the crowds.
On Sunday, about 20 businesses were ransacked by looters and the National Guard were deployed.
Vigils and protests were also held on Monday in Washington, New York, Portland and California.
Tensions were already high in the Twin Cities as the trial of former police officer Derek Chauvin for the murder of George Floyd continues in Minneapolis.
The shooting of 20-year-old Wright on Sunday happened just 10 miles away from where Floyd was killed in May 2020.
Protests erupted after Daunte Wright was killed on Sunday during a traffic stop in the suburb of Brooklyn Center
Police and National Guard were on standby to enforce a curfew imposed by Brooklyn Center's mayor
Police shot tear gas and stun grenades at protesters in an attempt to disperse the demonstrators