the hospital called in extra staff and diverted emergency ambulance patients to King's College Hospital and St Thomas' Hospital.
A Lewisham and Greenwich NHS Trust spokesperson confirmed the incident was "a precautionary step due to the high number of Covid-positive patients we are seeing at the hospital".
They added: "We have been following our plan to cope with a second wave of Covid-19 and are working closely with hospital and healthcare partners in south east London.
“All our patients have received the treatment they need, including intensive care treatment for Covid-19 and oxygen therapy as required. We are continuing to monitor the situation to ensure that this remains the case.”
A number of hospitals in London have been forced to declare incidents in the past fortnight as coronavirus cases rise in the capital.
Two Kent hospitals have issued capacity warnings after an influx of Covid patients.
One was reportedly forced to treat patients in the back of ambulances, with another so full of people waiting to be seen ambulances were queuing for hours.
Medics have warned of cases rising at "unprecedented levels" as hospitals feel the strain with admission numbers matching the April peak.
Dr Andrew Lansdown, a consultant endocrinologist at the University Hospital of Wales in Cardiff, said: "It's starting to sound a bit like a cliche but it really is true that these are unprecedented times, we really have felt stretched to the limit.
"In the past week or two things have become relentless, we're under extreme pressure and the numbers of patients coming through now with coronavirus are massive."
Dr Yvonne Doyle, Public Health England medical director, said: "This very high level of infection is of growing concern at a time when our hospitals are at their most vulnerable, with new admissions rising in many regions."
But she added: "Despite unprecedented levels of infection, there is hope on the horizon," referring to the current vaccine rollout.
ICUs in London are operating at 114 per cent Credit: PA:Press Association A huge surge in covid cases has sparked panic Credit: PA:Press Association Doctors have reported a lack of oxygen and beds at hospitals Credit: Getty Images - Getty Ambulances wait outside Guy's Hospital in London Credit: AFP or licensors The Nightingale Hospital at the ExCel centre now stands empty Doctors have described "staggering" numbers of Covid patients Doctors in Wales said the NHS is facing a "bleak" situation
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