Around 100 protesters, believed to be English Defence League supporters, are holding unplanned protests in two areas of Manchester.
There are also reports of a counter-protest by members of Unite Against Fascism in another part of the city.
Greater Manchester police have told ITV Granada that one person has been arrested on suspicion of a public order offence.
More top news
Labour have lost the Copeland by-election, a seat they had held since 1983, as the Conservatives edged the vote by 2,000 votes.
Labour have held onto the crucial seat of Stoke-on-Trent, brushing aside UKIP leader Paul Nuttall in the process.
A highly toxic chemical was used in the death of North Korean leader Kim Jong-un's half brother last week, tests have shown.