The West Yorkshire constituency where Labour MP Jo Cox was shot dead has been the site of numerous protests by Britain First in the past year.

Cox, 41, MP for Batley and Spen, was shot and stabbed to death after a constituency meeting in Birstall on 16 June.

Bradford and Dewsbury – both less than six miles from Birstall – have been repeatedly targeted by Britain First in recent months, becoming a hub for its activities.

The group's campaigning – sometimes taken by its "fast-growing Northern Brigade" – has come under close scrutiny in the past 24 hours after a witness claimed Cox's suspected murderer, Birstall resident Tommy Mair, shouted "Britain First" or "put Britain first" while allegedly carrying out the attack.

The party's leaders strongly denied any links with Mair and described the shooting as "a downright despicable act of criminality".

Paul Golding, leader of Britain First, also questioned whether Mair had shouted any phrase associated with his party. He said: "What this person said – was he referring to an organisation? Was this person referring to a slogan? Was he just shouting out in the middle of an EU debate: 'It's time we put Britain first?'"

Deputy leader Jayda Fransen told IBTimes UK: "I can categorically say Tommy Mair was neither a donor or a member of Britain First, and none of our activists had heard of him."

The party has been highly active in West Yorkshire over the past year, after Fransen had said it planned an "unprecedented" number of events for 2016.

The group describe Bradford, where it has leafleted and protested, as a "well known hotbed of Islamic extremism and colonisation". Dewsbury, the location of its first national march this year, was said by the group to be the "Islamist capital" of Britain.

Anti-extremist groups, like Hope not Hate and Unite Against Fascism (UAF), have in the past accused the group of stoking up anti-immigration sentiment and spreading hatred in the region. Britain First's leaders insist they are a peaceful political party which simply challenges current policies on immigration and Islam.

Here are some of the Britain First events to have taken place in and around Cox's constituency in the past year.

National march in Dewsbury - January 30

The party chose to hold its first national march through the streets of Dewsbury on 30 January. The protest focused largely on anti-Islam and anti-immigration themes.

Golding had said: "Dewsbury is the 'Islamist capital' of Britain and has produced many terrorists and Isis volunteers. We are going to Dewsbury, the beating heart of UK terrorism, to make a stand."

West Yorkshire Police had imposed restrictions on the protest beforehand, forcing the group to change its route and barring them from holding placards marked, "No More Mosques". Arrests were made on the day after anti-fascist campaigners staged a counter protest.

One opposition group called We Are Dewsbury said in a statement: "We urge members of the local and neighbouring communities and further afield to come and show their support by standing up against fascists and racists such as Britain First and others who seek to divide our communities."

Cars smashed up in Bradford

A visit to Bradford city centre about two weeks later, on 13 February, saw about 40 activists hand out anti-immigration literature to residents and shoppers.

Two of the group's vehicles were smashed up during the leafleting, with Britain First blaming it on "local Muslim extremists". Two local men were later arrested for the vandalism.

The day also saw West Yorkshire Police issue Britain First activists with dispersal notices, requiring them to leave the city and West Yorkshire county. These are usually issued to prevent further disturbances between groups and individuals.

Mosque invasions in Bradford and Dewsbury

The group's Northern Brigade visited 26 mosques across Dewsbury and Bradford in a "day of action" against Islam in October 2015. The group has been criticised in the past for the so-called "mosque invasions", with founder Jim Dowson quitting the party after describing them as "provocative and counter-productive".

During a day, the group said they intended to speak to imams about "extremism and grooming gangs", adding: "Our teams also confronted several Muslim extremist stalls in the town centres and told them if they wanted 'Sharia Law' they should go back to the Middle East."

It added: "The Northern brigade is growing stronger and more and more activists are joining the units."