A Belfast leisure centre has been closed amid mounting tensions over a council decision to remove a loyalist bonfire built in its car park.

Avoniel closed its doors early this afternoon, shortly after loyalists called for supporters to gather at the site for a rally to protest against the planned intervention.

There have been calls for calm, with concerns an attempt to demolish the controversial structure could prompt an angry backlash.

Belfast city councillors earlier reaffirmed the decision to send contractors, under police escort, to take down the bonfire.

A council committee had reconvened to reassess the situation following a move by the bonfire builders yesterday evening to remove hundreds of tyres from the bonfire.

The decision remained unchanged, with a council spokeswoman saying the authority was acting in the interests of protecting life and property.

However, unionist parties in the council, which were in the minority on the committee, expressed disappointment at the decision.

Huge bonfires will be lit in loyalist areas late on Thursday night to usher in 12th of July, the main date in the Protestant loyal order marching season marking the 1690 Battle of the Boyne.

While most of the fires are lit without major incident, a number continue to prove contentious, with the authorities having taken action in recent years on towering structures deemed unsafe and posing a threat to nearby properties.

The gates of the Avoniel centre were barricaded on Sunday in a pre-emptive bid to prevent police and contractors accessing the site, forcing the centre to close early for the day.

This afternoon, the gates were again barricaded. Industrial bins and tyres were placed in front and behind them and a secondary barricade - made up of tyres - has been built further into the car park entrance.

Earlier, a delegation representing the bonfire builders met police at a city centre station to urge them not to intervene to support the removal of the bonfire.

They insisted taking away the tyres has rendered the bonfire safe and warned its demolition would be unjustified and could lead to community tension spilling over.

Outside Musgrave Street police station, Robert Girvin, a representative of the bonfire builders from the East Belfast Cultural Collective, urged councillors to hold direct talks with loyalists.

"Have dialogue with us," he said. "Tell us exactly what your issue is with this bonfire."

"And let us know exactly - apart from your attempts to erode our culture - what is the issue?"

Yesterday the Strategic Policy and Resources Committee voted to use contractors to remove materials from the Avoniel site and another at nearby Ashdale Street car park.

Bonfire builders subsequently relocated the Ashdale Street fire to another site close to Mersey Street.

However, the Avoniel bonfire remains on site, partially constructed and with tyres removed, with builders showing no inclination to relocate it.

Early on Sunday morning, police supported masked council contractors as they removed about 1,800 tyres from a bonfire off London Road in south Belfast.

Sinn Féin councillor Deirdre Hargey said site assessments from statutory agencies reported that the Avoniel bonfire posed a "significant risk" to nearby property.

"As a council and public authority on which this bonfire is situated on our land we have to react to that for the public interest," she said.

Ms Hargey said the council had received reports of intimidation at the site on Monday night, with the gates again closed off. She claimed firefighters were told they were not welcome when they responded to a small fire lit on the site.

"This is a concerning issue, it's a public safety issue," she said.

Alliance city councillor Emmet McDonough Brown said: "This was never just about tyres in the bonfire - this was about other issues around damage to public property and private property.

"The fact this is a ratepayer-funded leisure centre which attracts people from across the community and those people have to be considered in this too.

"So I don't think it's fair to have a bonfire in a leisure centre which belongs to a public body."

A statement from DUP councillor George Dorrian, Progressive Unionist Party councillor John Kyle and Ulster Unionist councillor Jim Rodgers said: "We are disappointed that the SP&R committee chose not to build on the progress made by bonfire builders when they removed the tyres yesterday evening from Avoniel bonfire.

"This year has seen a dramatic improvement in the situation around bonfires throughout Belfast. We have spent months engaging with groups across the city and real progress is being made.

"We are confident that the community will fully enjoy the celebrations peacefully and respectfully.

"We urge those who are angered by the decision not to respond in a negative way which serves only to undermine the arguments made by unionist representatives at today's and previous committee meetings."

In Portadown, Co Armagh, residents of three apartment blocks in the Corcrain area have been urged to evacuate their homes due to concerns about the size of the bonfire built close-by.

It is understood Armagh City, Banbridge and Craigavon Borough Council has been unable to secure a contractor willing to take down the bonfire, having approached more than 35 companies.