Towering bonfires have being lit in loyalist areas across Northern Ireland to usher in the Twelfth.
A number of small pyres, mainly constructed by stacking wooden pallets, were set alight late on Monday evening with the majority ignited at midnight.
Police said a number of complaints had been received about flags, effigies and election posters being placed on bonfires and officers would review evidence to establish if offences had been committed.
More than 250 bonfires have been constructed in loyalist neighbourhoods across Northern Ireland.
The fires are traditionally ignited on the eve of the "Twelfth of July" - a day when members of Protestant loyal orders parade to commemorate the Battle of Boyne in 1690.
The battle, which unfolded at the Boyne river north of Dublin, saw Protestant King William of Orange defeat Catholic King James II to secure a Protestant line of succession to the British Crown.
This year's events have been overshadowed after the death of bonfire builder John Steele. He was helping to build a structure in Larne's Antiville area when he fell.
Police and the local council are investigating.
Meanwhile, a neighbouring bonfire at Craigyhill has been reported to have broken a world record for the tallest bonfire. It was reported to be over 200ft in height.
Hundreds of people watched on as the bonfire was lit at midnight with organisers confident that they had broken the world record for the tallest bonfire, after the pyre was measured at 202.3ft.
Nearby houses had their windows boarded up and the fire service hosed down properties to protect against the heat of the massive bonfire.
Another fire lit at midnight was at Adam Street in the loyalist Tigers Bay area of north Belfast.
Nationalist residents from the nearby New Lodge estate have previously claimed the fire is located too close to the interface between the two communities - something the bonfire builders have denied.
The PSNI is planning for the Twelfth to be their busiest and most resource-intensive day of the year, with the Eleventh Night being second.
There will be 2,500 police officers on duty on the Twelfth, which is around a third of the strength of the PSNI.
There will be 573 loyal order parades later. Of these, 33 follow routes that are deemed to be sensitive.
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