Dissident republicans were responsible for a volley of automatic gunfire on police in Derry on Tuesday, the PSNI have said.
In a fourth night of violence, six shots were fired at officers close to the city’s famous walls.
None of the officers were injured and the bullets were found both in the walls themselves and nearby trees.
It is believed the shots were automatic gunfire which came from the vicinity of the Bogside Inn.
Around 16 petrol bombs and five paint bombs were also thrown close to the walls and at police patrols.
The Police Service of Northern Ireland (PSNI) are treating the incident as attempted murder.
The Terrorism Investigation Unit has started investigations into the incident.
District Commander Superintendent Gordon McCalmont said they believe dissident republicans fired the shots, and engineered the recent disorder.
“Officers who were in the city last night to deliver a community safety operation are wakening up this morning trying to come to terms with what could have been.
“We are offering them every support,” he said.
“It is quite clear that this attack was carried out by violent dissident republicans who we believe engineered the disorder we have seen in the city over the last number of nights.
“While this is a serious and disturbing escalation it will not deter us from doing our job and that is protecting the people of this district.”
Northern Ireland Secretary Karen Bradley led condemnation of the incident.
“Anyone, who was in this part of the city, at this time, including children or young people could have been killed,” she said.
“This murderous attack has to be condemned by all right-thinking individuals.
“I would call on all people of influence within the community to continue their efforts to encourage dialogue and reduce tensions.
“Anyone with any information about these incidents should contact the police.
“We will continue to work with the police to keep people safe.”
Earlier, the leaders of all of the main political parties united to condemn attacks on the police amid ongoing unrest in Derry.
The DUP, Sinn Fein, Ulster Unionists, SDLP and Alliance issued a rare joint statement condemning the attacks and calling for an end to the violence.
They said: “Attacks on the police have been ongoing for a number of days alongside other violence including sectarian attacks on houses, petrol bombs thrown at the police, intimidation of contractors, vehicles hi-jacked and attacks on sheltered accommodation.
“The shots fired last night were a clear and obvious attempt to murder police officers.
“There must be a strong, clear and united voice against those who would engage in such disgraceful violence.
“As a society we must all stand with those who maintain law and order and who protect all sides of our community.
“We condemn any illegal activity and urge those who are damaging their own community and intimidating their neighbours to stop.
“We would urge people to work with the police to bring those involved in criminality to justice.
“We want to see a society where people can live together without the threat of intimidation or violence.
“Those who engage in such tactics must be shown that they will not succeed.”
The Police Federation for Northern Ireland (PFNI) described the shots fired in Derry as “an act of pure evil”.
PFNI chairman Mark Lindsay said officers deserve the support of the entire community.
“This attack last night was an act of pure evil, and attacks like this have got to stop,” he said.
“We have to see an all-out effort being made to rid communities of these ‘dinosaurs’ and to allow people to get on with their lives.”
IForeign Affairs minister Simon Coveney urged those behind the violence to stop, and welcomed the issuing of the joint statement from the local parties.
“I am very concerned at the escalation of the violence in Derry overnight,” he said.
“It is clear that shots were fired in an attempt to endanger the lives of PSNI officers in the area.
“The ongoing reckless endangerment of lives, which is being orchestrated by a small and violent minority, must stop.
“I welcome the statement from the leaders of the main political parties in Northern Ireland which called for communities to stand together to protect the rule of law.
“This joint statement is a testament to the continuing good relations that have been built up in the city over many years.
“This unity will not be challenged or destroyed by the criminal and sectarian actions of a small number of individuals.”