Police have appealed for calm after a petrol bomb was thrown at officers in Londonderry on Wednesday night.
It happened in the Bishop Street area, police said, adding there had been a number of incidents of antisocial behaviour in the area between 20:00 and 23:30 BST.
Police Service of Northern Ireland (PSNI) Ch Supt Gillian Kearney said police believed the removal of bonfire material from under Lecky Road flyover in the city's Bogside early on Wednesday morning "prompted the initial incidents last night".
But she said antisocial behaviour in relation to the Fountain Estate and Bishop Street interface "also played a part".
"We hope we do not see a repeat of what occurred last night, however, I want to reassure the community we will deploy the necessary resources to detect and deter those responsible and keep people safe," she said.
Kearney added: "We appeal for calm. There is no need or point in bringing disruption to local communities, and there will be consequences for those found to be involved."
Earlier Stormont's Department for Infrastructure (DfI) said it removed the bonfire material from under the flyover because of a fire risk due to nearby underground gas mains.
A DfI spokesperson said that the "illegal storage" of the pallets under the flyover posed a "significant fire safety risk" as there were gas mains under the tarmac.
The Lecky Road was closed for a time following the initial removal of the materials, with police saying some items had been set on fire on the road.
It closed again later on Wednesday night when police said pallets and a mattress were set alight on the flyover while a motorbike was also seen to be on fire.
Speaking to BBC Radio Foyle's North West Today programme SDLP councillor John Boyle said it was important "everyone remains calm over the next 24, 48 hours."
Boyle said initially it had been thought there was to be no bonfire in the Bogside this year.
But, he said, in recent days "a real possibility that any prospective bonfire may well have going to be built on the road" had emerged.
"That presented a real problem for the local neighbourhood, local people, a real threat to life and a real threat to property," Boyle said.
"There's a major gas pipeline which sits just inches underneath the road network in that and that neighbourhood," he said.
A bonfire in the Bogside has attracted large crowds in recent years but has also faced some criticism over the burning of poppy wreaths, as well as unionist flags and symbols.
A bonfire was previously built on the flyover - a main road in and out of the Bogside area of Derry - in 2016.
Speaking in Derry on Wednesday, First Minister Michelle O'Neill welcomed the removal of the materials.
O'Neill said: "I commend those who have removed the pallets and everything else, all the material, because none of us wants to see these anti-social bonfires in our community."
Boyle said more than 450 pallets had been removed on Wednesday morning.
They had, he said, been removed from a storage bay or tunnel underneath the flyover.
"That's an awful lot of pallets. They were obviously stored very surreptitiously and in a very clandestine manner because it took the local people who live in the neighbourhood completely by surprise," Boyle said.
Boyle said the DfI must now clarify if the approach taken in the Bogside is one "that they're going to be taking in relation to storage of bonfire materials on their property irrespective of where it is and irrespective of who's building a bonfire and why they're building that particular bonfire".