The World Health Agency is investigating reports of mild cases among children in the United Kingdom, Spain, and France, as the "ongoing transmission" of monkeypox worldwide could lead to the virus spreading to high-risk groups, such as pregnant women, people with immunodeficiency, and children.

On Wednesday, the World Health Organization said it is investigating reports of infected children, including two cases in the UK, as well as monitoring reports in Spain and France, but none of the cases in children were severe.

The virus has now been identified in more than 50 new countries outside the African countries where the virus is endemic. The World Health Organization said cases are also rising in those countries and called for intensified testing.

WHO Director-General Tedros Adhanom Ghebreyesus said, "I am concerned about the continued transmission of the virus because it indicates that the virus is establishing itself and can spread to high-risk groups including children, pregnant women, and those with immunodeficiency."

The World Health Organization described sustained transmission as a disease that can easily spread from person to person among the population, and monkeypox is usually mild and endemic in parts of West and Central Africa. It spreads through close contact, so it is relatively easy to contain through measures such as self-isolation and hygiene.

At least 235 cases of monkeypox have been confirmed in Canada, according to the latest official numbers from the Primary Health Care Center, last updated on Friday.

This includes 184 cases in Quebec, 45 cases in Ontario, four in Alberta, and two in British Columbia.

The WHO warning comes days after it stated that the global outbreak should be closely monitored but does not warrant declaring a global health emergency.

In a statement on Saturday, the WHO Emergency Committee said many aspects of the outbreak were "unusual" and acknowledged that monkeypox – a disease endemic in some African countries – has been neglected for years.

The WHO said in a statement, "While a few members expressed differing views, the committee unanimously decided to inform the WHO Director-General that at this stage, the outbreak should not be determined to constitute a "public health emergency of international concern."

However, WHO pointed to the "urgent nature" of the outbreak and said controlling its spread requires an "intense" response.

The committee said the outbreak should be "closely monitored and reviewed in a few weeks." But it would recommend reassessment sooner if certain new developments occur, such as cases among sex workers, if it spreads to other countries or within countries already affected, or if the severity of cases or the transmission rate increases.

Edited by: Dima Abu Khair