Fire crews were called to at least six Eleventh night bonfires, dousing one property with water jets to prevent it igniting.
Half of the incidents, all reported between 6pm and 9pm, needed urgent action to ensure the safety of homes.
At one, crews used main jets to cool nearby sheds in order to ensure heat from a large bonfire didn’t set them alight.
Beacons lit up across the province last night ahead of today’s Twelfth celebrations — but some were again marred by controversy over sectarian and racist effigies and banners.
Among the biggest was at Lanark Way in west Belfast.
But as darkness fell and the flames began to rise, condemnation continued of the placing of election posters and flags on top of some of the pyres.
Last night Gerry Adams added his voice to a series of calls from politicians for the removal of campaign posters and effigies placed on bonfires.
It came after a representation of the Sinn Fein president hanging from a pretend gallows was placed on a bonfire in Ballycraigy.
Mr Adams described it as a “deeply offensive and a clear hate crime”.
“The Orange Order claims that bonfires are an important part of Protestant culture and should be welcoming to families,” he said.
“The figure of a lynch victim on a bonfire is not a welcoming sight for anyone. This is a disturbing escalation of sectarian and hate crime.
“The Orange Order must take immediate steps to have it removed.”
Last night an Orange Order spokesman said: “The Grand Orange Lodge of Ireland does not organise bonfires; however, we would urge those involved to act responsibly.”
Elsewhere, an effigy of Sinn Fein's Niall Ó Donnghaile, a former Lord Mayor of Belfast, was placed on top of Cluan Place bonfire in east Belfast and a banner displaying racist abuse about Hong Kong-born Alliance MLA Anna Lo appeared on a bonfire in Orangefield Park.
Alliance councillor Laura McNamee condemned those responsible for the banner about Ms Lo, saying she was appalled by it.
“Statutory agencies should take action against those bonfires which contain tyres, posters, flags and offensive banners. This does not constitute a positive expression of cultural identity; it merely seeks to offend others,” she said.
A police spokeswoman last night said: “Police are aware of numerous items, some of which can only be described as distasteful, that have been placed on bonfires in a number of parts of Northern Ireland.”