British Immigration Minister James Brokenshire said in a statement to CNN that he was "deeply concerned by this issue" after media reports that asylum seekers had had eggs and stones thrown at their houses because the paintwork on their doors gave away their immigration status.
Brokenshire said he had instructed officials to conduct an urgent audit of asylum seeker housing in England's North East region, where Middlesbrough is located.
"If we find any evidence of discrimination against asylum seekers it will be dealt with immediately, as any such behavior will not be tolerated," he said.
The company responsible for asylum seeker housing in the region, G4S, told CNN in a statement that there was "categorically no policy to house asylum seekers behind red doors."
A subcontractor working for G4S, Jomast, had used red paint on all properties serviced by the company. "It's grotesque to equate this with any form of discrimination," G4S said.
While G4S had received no complaints from asylum seekers relating to the paintwork, the subcontractor was going to repaint affected doors so that no color predominated, the G4S statement said.
Suzanne Fletcher, a former local councilor in the area, said in an interview with BBC's Radio 4 Today Show on Wednesday that she had raised the issue with G4S in 2012, but the company had taken no action.
Swedish PM: New migration system needed
European countries are facing the biggest migration crisis since World War II. Last year, more than 1 million migrants crossed into Europe
through "irregular arrivals," with some governments, notably Germany, welcoming them, and others, like Hungary, taking a hardline stance against them.
As world leaders gathered in Davos, Switzerland, for the World Economic Forum on Wednesday, Swedish Prime Minister Stefan Löfven told CNN's Nina dos Santos that Europe needed a new migration system, and all 28 member EU states were taking part in discussions to achieve this.
He was responding to media reports that the European Union
is planning to rewrite migration rules in the face of the overwhelming numbers of migrants fleeing conflict, persecution and poverty in the Middle East and Africa.
Sweden -- along with Germany, a favored destination for migrants -- was one of three or four countries taking "huge responsibility" for migrants, and other countries need to do more, he said.
"It's a very serious situation," he said, adding that the crisis posed a threat to the Schengen Agreement, which allows for borderless travel between participating European countries.
Löfven said it was also important to tackle the issues driving migrants to leave in the first place. To that end, Sweden was stepping up its fight against terrorism, he said.
More than 500 women report sex assaults in Cologne
Tensions surrounding the migrant crisis have only heightened this year, after mob sex attacks in the German city of Cologne and elsewhere blamed on migrants from the Middle East and North Africa.
Similar incidents were reported across Europe on New Year's Eve from Zurich to Helsinki, with at least 50 similar incidents reported in the German city of Hamburg.
The Cologne prosecutor's office said Wednesday that 834 criminal complaints had been received regarding the crime wave in the city center on New Year's Eve, which led hundreds of women to report having been groped and molested by gangs of men.
The prosecutor's office said the complaints related to 943 victims, 523 of whom reported being victims of sexual assault.
Eight men are in pretrial custody over the assaults, the office said.
The attacks sparked angry protests, claimed the job of city's police chief for his department's handling of the episode, and prompted a German broadcaster to issue an apology for its slowness in reporting the assaults, amid public criticism that the incident was initially covered up out of political correctness.
German officials last week outlined plans for lowering the threshold for foreigners to be deported
to include convictions for sexual or physical assaults or resisting police officers. Previously, only those sentenced to crimes punishable by a sentence of one year or more could be deported.
Cologne police last night swept the city's Kalk district, searching pubs and betting offices in the neighborhood that police described in a statement as a "safe haven" for North African criminals.
In a statement, police said that 120 people and 79 mobile devices were searched, and arrests were made on drug and firearms charges.
Clashes at Dutch protest against asylum center
The small Dutch town of Heesch became another flashpoint in Europe's migration crisis Monday night when clashes erupted during protests against plans to open a center for asylum seekers in the town.
The protest, organized on a Facebook page that has more than 3,100 likes, called for demonstrators to rally outside Heesch's town hall.
According to a statement on the municipality's website, police in the town had been granted extra powers to deal with the situation Monday night after the demonstration ran out of control.
Norway deports migrants
And Norway has sent 13 migrants back across the border to Russia, according to Norwegian public broadcaster NRK.
Russia does not allow pedestrians to cross there, while Norway penalizes drivers who transport asylum seekers, leading asylum seekers to take to two wheels for the crossing.
But after the introduction of stricter asylum policies, Oslo has begun deporting the recent arrivals. NRK quoted a police spokesman as saying that those sent back to Russia on Tuesday night had had their bid for asylum in Norway rejected.