BELFAST BRIEFING:When Tyrone designer Rory O'Loughlin won the chance to sell his inventions at the Belfast Christmas market this year he was hoping it would go down a storm. O'Loughlin, who owns Omagh-based Loughlion Design, was delighted to get the chance to sell his "frogjaw" design – a quirky cooking utensil attachment – on his all-expenses-paid stall at the market.

On average 800,000 people visit the market in the grounds of City Hall each year so it is the perfect opportunity for budding entrepreneurs to test the water.

O’Loughlin’s expectations were probably quite high for his frogjaw design. It had already proved a hit when it was showcased at the 2012 London Design Festival.

But what he and the other 80 traders at the market were definitely not expecting was the fact that it would be operating against a backdrop of a highly charged atmosphere in the city this festive season.

Ugly protests over Belfast City Council’s decision to fly the union jack flag at City Hall on certain days rather than every day have spiralled into violent unrest and attacks on Alliance Party politicians.

Last Saturday, on what should have been one of the busiest shopping days of the year, scores of businesses in Belfast city centre and the Christmas market closed while up to 2,000 people protested the flag decision. The protest may have passed off without violent scenes but when a city has to close its Christmas market temporarily it speaks louder than words about what is going on behind the Santa scenes.

According to Joe Jordan, president of the Belfast Chamber of Trade and Commerce, the recent media images of violence returning to Northern Ireland’s streets have been deeply regrettable. He is concerned about the impact they could have on tourists and visitors who had considered coming to Belfast.

“Belfast was having a really good run up to Christmas. What we don’t understand is why politicians – people who are elected to take the right decisions for this city – could not have waited to hold the debate about the union flag until after Christmas. Everyone knows the union flag is such an emotive issue not only in Belfast but in the country as a whole,” Jordan said.

That the violence happened at the same time as the US secretary of state just happened to be on an official visit to Northern Ireland means the impact of the unrest could be more damaging. Images of burning cars and riots are hard to displace in the minds of wary potential investors.

Hillary Clinton warned in Belfast last week that violence was never an acceptable response to disagreements. But behind the flag protests and unrest there is another more serious issue in the North that is not being addressed. It is one the US secretary of state chose to highlight. She said “the promise of peace” must be delivered in Northern Ireland. “There has to be an economic return for people here.”

She said: “I want to offer a cautionary word because, if we do not focus on a community level, on that interface, we will not have really achieved the peace that has been worked for. Let us reach out to those who do not yet feel in their heart what has been achieved.”

It would be interesting to find out just how many of the people involved in the unrest last week are currently out of work or are long-term unemployed.

The unrest may have been contained to very small pockets and it may have involved a limited number of people but 28 police officers were still injured and it will still have cost the city revenue in one way or another.

According to Invest NI, the unrest did not impact on “any scheduled visits” organised by the agency. But it says that the whole affair has been “unhelpful as we work to sell Northern Ireland as an attractive location for investment”.

Not exactly the kind of early Christmas present that anyone wants.