The two people who live in the same household have been diagnosed with the rare infection in London, the UK Health Security Agency (UKHSA) said. They are not linked to the previous case in England which was announced on May 7.
One of the latest cases is being treated at the expert infectious disease unit at St Mary’s Hospital, Imperial College Healthcare NHS Trust in London.
The other person is isolating and does not currently require hospital treatment.
Health officials said they are investigating where and how the two people picked up the disease.
Close contacts of the cases are being contacted and given information and health advice.
Health bosses said monkeypox does not spread easily among people and that the overall risk to the general public remains “very low”.
Dr Colin Brown, director of clinical and emerging infections at the UKHSA, said: “We have confirmed two new monkeypox cases in England that are not linked to the case announced on May 7.
“While investigations remain ongoing to determine the source of infection, it is important to emphasise it does not spread easily between people and requires close personal contact with an infected symptomatic person.
“The overall risk to the general public remains very low.
“We are contacting any potential friends, family or contacts in the community.
“We are also working with the NHS to reach any healthcare contacts who have had close contact with the cases prior to confirmation of their infection, to assess them as necessary and provide advice.”
Dr Brown said the UKHSA and the NHS have “well established and robust infection control procedures for dealing with cases of imported infectious disease and these will be strictly followed”.
Professor Julian Redhead, medical director at Imperial College Healthcare NHS Trust, said: “We are caring for a patient in our specialist high consequence infectious diseases unit at St Mary’s Hospital.
“All of the necessary infectious control procedures have been followed and we are working closely with UKHSA and NHS England.”
Monkeypox is a rare infection mainly spread by wild animals in parts of west or central Africa.
The risk of catching it in the UK is very low, according to the NHS.
It takes between five and 21 days for the first symptoms to appear after becoming infected.
Symptoms include a high temperature, headache, muscle aches, backache, swollen glands, shivering and exhaustion.
A rash usually appears one to five days after the first symptoms which is sometimes confused with chickenpox.
The rash starts as raised spots which turn into small blisters before eventually forming scabs and falling off.
Monkeypox is usually mild and most people recover within a few weeks.
People normally stay in a specialist hospital so the infection does not spread.