The emergency services were called out to an alert to a nature reserve this evening.
Residents in Lizard Lane and neighbouring streets say they saw a number of police officers to Marsden Old Quarry Local Nature Reserve this evening.
Northumbria Police confirmed it had been called to the street, but offered reassurance there was no risk of harm to the public and said it was unable to give further details.
The call out happened at around 6.30pm and led the emergency services to an area of the former quarry, opposite the entrance to Lizard Lane caravan park.
Marked police cars and the ambulance service were seen parked up at the foot of Lizard Lane bank and close to the turning circle.
One 49-year-old man who lives nearby said: "I saw about four or five police cars and a couple of them had their lights flashing and the ambulance had its siren on.
"I saw a lot of them running towards the hills, uniformed officers."
A 54-year-old man said: "I had finished work and I saw the police van and heard the sirens.
"I saw the police cars and ambulance pull up."
Paramedics were also seen entering the former quarry, which leads to Cleadon Hills and is bordered by a pathway which leads to the other side of Quarry Lane and the Grey Horse pub.