Hundreds of tyres have appeared on bonfires across Northern Ireland, sparking fears of toxic clouds over Northern Ireland on the Eleventh Night.

UUP councillor Jim Rodgers said it appeared there had been a spate of deliveries under cover of darkness.

Burning tyres releases a deadly cocktail of more than 100 chemicals into the air, with the fine particles able to settle in people's lungs. They can lead to heart problems and are also carcinogenic.

Mr Rodgers' comments came after an open truck was photographed shedding its load of tyres onto a bonfire site in the Ballybeen estate in Dundonald, in the Lisburn & Castlereagh City Council area, on Wednesday night,

That same night, scores of tyres appeared on an east Belfast bonfire funded by Belfast City Council, although they were later removed.

The environmentally unfriendly addition to the pyre in the car park beside Avoniel Leisure Centre was potentially embarrassing for the council because that particular site is part of its official bonfire programme.

Under the scheme, funding of up to £1,000 is available to participants who meet a strict set of guidelines.

If they only fulfil half of the requirements, however, they can still get half the money, meaning that the council gives ratepayers' cash to people responsible for illegal bonfires.

The Avoniel fire is next to hundreds of homes and a number of businesses.

Mr Rodgers, who is Belfast High Sheriff, said it was "deeply concerning that this happened at such a late hour".

"The fact that they had tyres on it is breaking one of the rules under the council's bonfire programme," he added.

"No money has been handed over just yet - that's the most important thing - and we'll continue to monitor the situation.

"We had numerous complaints from residents and traders in the area, expressing their concern and asking for decisive action to be taken."

The UUP man also insisted that he and his fellow councillors were actively monitoring the Belfast area to stamp out any potential dangers ahead of the Eleventh Night celebrations next week.

"Myself and my colleague (UUP councillor) Sonia Copeland spoke to the council about the Avoniel bonfire and asked them to speak to those responsible for it," he explained.

"We're pleased we managed to get a resolution to this because that's an extremely built-up area with hundreds of residents and a lot of businesses as well.

"There are a lot of young people and older people, you have the leisure centre and the school and Connswater Retail Park is close by.

"It's also on the flight path into and out of Belfast, so I'm particularly concerned about the potential effect of black smoke on planes en route to and from George Best Belfast City Airport because these fires can smoulder for quite some time. We must avoid putting unnecessary pressure on the Northern Ireland Fire and Rescue Service and potentially the Ambulance Service, which we know is struggling right now."

Mr Rodgers stressed that he did not want to stop anyone lighting traditional bonfires, but he added that they must build them with respect to health and safety legislation.

"There are major health reasons why you cannot light fires - the toxic fumes from them are absolutely deadly," he added.

"We must establish where these tyres are coming from. There have been suggestions that members of the Travelling community and tyre suppliers themselves have been responsible.

"I have continually asked the police to be more proactive in trying to ascertain where they're coming from because many of these tyres are being transported in trailers and open vehicles, not vans."